Gravity Falls RP! You take the place of Fiddleford McGucket. Prompt: POV: You receive this letter. WDYD? (My usual rules apply)

(I don’t have a image Bcs my acc is new *cri*)
Theo: *he immediately folded up the letter and headed back to town, also, are you alright with ocs that are mute?*

*He approached the shack and checked his pocket watch. He dropped his cigarette and crushed it under his boot, then walked up and knocked on the door.*

It's not like I can just do that. I dismantled the portal and used it for spare parts, so I can't go back. If you could just try out the arm to make sure it actually works, I'll give you anything you want that I can actually give you. *He holds the ultra-efficient Automail arm out to Heckyl*

Heckyl: "No. We have to give the arm to the alternate me. It's too big a discrepancy. You probably noticed that each alternate version of me is missing his right arm. Even one alternate version who isn't missing an arm could cause a temporal rift, which itself could result in irreparable damage to the multiverse."

We must rebuild the portal immediately. Luckily, I still have all of the blueprints and calculations, and I can safely dismantle everything I used portal parts to make. I know I traumatized you last time, but this time, we need to make sure that the rope of the test dummy isn't tangled around your ankle. If we don't do this, the multiverse won't exist. How many spare arms do you have?

Heckyl: "If you have enough scrap metal to equal to the weight of the portal, then I can transmute it with alchemy."

I mean, the portal is almost fully intact, I just need all of your spare arms to give to any possible parallel versions of you who don't have Automail arms. *He grabs a strange contraption and disassembles it, putting specific parts on the dismantled portal*

(His name is Raleigh Heckyl, though he goes by Heckyl)

It's for the same purpose as the vending machine door. Keeping out snoopers. *Ford pulls out a key and unlocks the door to the elevator with said key*

Heckyl: "Fair enough."

*He stepped in the elevator.*

Heckyl: "Still redundant."

(I changed his appearance slightly. He has black eyes now, but everything else is the same)

(Ight)
*Once they get to the bottom of the elevator, to the lab, Ford opens the elevator doors and exits the elevator. He then walks over to a shelf and picks up a mechanical structure* This is what I wanted to show you. An upgraded version of your prosthetic arm that is lighter, more energy efficient, and needs oil and screw changes less often.

*Heckyl was stunned.*

Heckyl: "That shouldn't be possible. Automail was only invented in the last, what, two years? That must me at least ten years old..."

(Note: Fullmetal Alchemist takes place in the 1910s. Assuming that Automail was invented in 1912 like I assume, it would be 1914 at least. Is that okay?)

(This was meant to take place in early autumn 2012, after the events of Gravity Falls, but I guess I can do that.)
Well, you know how quick I am to improve new inventions. I can switch your current arm out for the new one if you want to test it out.

(I can fix the timeline, but I'd have to change a few things. Nothing major, just some parts of Heckyl's backstory would have to shift, like his involvement in the Ishvalan War of Extermination, but we can do that timeframe if you'd rather.)

*He shook his head.*

Heckyl: "No. This is a temporal anomaly."

*He took the arm.*

Heckyl: "This model is too advanced to exist today. My current prosthetic is the most advanced model you can get. We need to figure out the origin of this arm before we attach this thing to my nervous system."

(Let's go with the 2012 timeframe and just move Heckyl's backstory forward in time to make it make more sense technologically.)
Well, the portal did take me through the multiverse. I actually made this in an alternative timeline where humanity was more technologically advanced in this time than it is now here in our timeline.

*Heckyl side-eyed Ford.*

Heckyl: "Does alchemy exist in this universe?"

Indeed it does. It was actually used by the parallel version of you who helped me create the ultra-efficient Automail arm. Between him and you, the only physical difference was that he had a normal arm instead of an Automail arm.

Heckyl: "Then cut his arm off."

(Thank you for this! It means a lot.) [Just call Stanford "Ford" instead of "Stanford"]
*Ford opened the door with a crossbow in hand, looking completely paranoid, and shouted* Who are you!? Have you come to steal my eyes!? *Once he got that out of his system, he blinked a couple times and said* My apologies, Heckyl, I thought you were a killbilly. Come in. Like I said in the letter, there's something I need to show you.

*He nodded.*

Heckyl: "This had better be important. I spent half of my research grant for the year getting out here."

*He followed him inside and withdrew a fresh cigarette.*

Heckyl: "Got a light? And some oil?"

(Quick context: Heckyl's right arm is automail, a type of advanced prosthetic that is connected directly to the nerves, though it costs a lot more and requires more maintenance. Heckyl made his arm so that it only really needs oil every once and a while, but he still changes things like screws and bolts every six months, or a year at the latest. As a running gag, he seems to constantly get shorter and taller. His base height is 5'9, but he may shrink inexplicably to a minimum of 5'3 or grow to a maximum of 6'1, though this is only used for jokes. His true height is 6 feet even.)

I do, actually. *He goes over to a nearby cabinet and grabs an oil tin and a lighter* Here you go.

*He filled the lighter with oil and lit his new cigarette.*

Heckyl: "Thanks. So what's this thing you had to show me?"

*His eyes light up the moment Heckyl brings up the thing that he was going to show him* Oh, it's something I think you'll enjoy. Follow me to the old lab. *He starts walking towards a vending machine*

*He followed.*

Heckyl: "...A vending machine?"

The vending machine was added over the door after you quit the portal project. I added it to keep snooping eyes away. *He reaches up and inputs "A1BC3" on the vending machine buttons, and the vending machine shifts away to open the door to the lab*

Heckyl: "Sneaky. But why would people be interested in snooping around some old military files, anyways? That project was abandoned a long time ago."

I have since dismantled the portal and used it for spare parts for other projects. In fact, some components of the portal were used in the creation of the thing I need to show you. *He leads Heckyl down a staircase to an elevator*

*He followed.*

Heckyl: "Remind me why we built an elevator at the bottom of this staircase instead of an elevator that goes all the way up, because in hindsight it seems redundant."

jeez the old shack is falling apart! where are you at Stanford? (the usual character Cosmo :] )

[Just call Stanford "Ford" instead of "Stanford"]
*Ford opens the door with a crossbow in hand, looking completely paranoid, and shouts*

"Who are you!? Have you come to steal my eyes!?"

*Once he gets that out of his system, he blinks a couple times and says*

"My apologies, Cosmo, I thought you were a killbilly. Come in. Like I said in the letter, there's something I need to show you."

a killbilly? Stan what's gotten into you?

"This happens a lot when I get unexpected visitors. And you never sent back a letter, so I didn't know to expect you. Wrongs on both parties, mine being much worse."

*Ford steps aside to let you in, setting down his crossbow in the process*

*Cosmo enters* I probably should have written back. what did you need to show me anyways?

"Come with me."

*Ford leads Cosmo to a vending machine*

alright? what are you doing with the venting machine?

"I put this vending machine in front of the door to our lab, as a measure to keep prying eyes away."

*Ford reaches up to the buttons and presses the combination "A1BC3", opening the door*

woah! what's down there?

"Our old lab is down there. The staircase that leads to the elevator, while it is redundant, is still serving its purpose of keeping prying eyes as far away from the lab as possible."

oh so I see well lets head on down shall we? lead the way!