This pilot has never aired on television, but the full episode was uploaded back in 2016 after Cipher Hunt, as a prize for the completion of the puzzle.

I saw this pilot on the original website and it was originally low quality when it was uploaded. The popular upload of it on Youtube is even lower quality, somehow.

I had nothing better to do today so I decided to upscale it to 1080p for anyone who wanted it. I think it turned out pretty decent!

You can find the original source here:
http://themysteryofgravityfalls.com/pilot/
Username: "RETURNBACKWARDS"
Password: "TOTHEPASTAGAINTHREE"
(without the quotations)

My Discord: https://discord.gg/GteFWaVp4t