[REQUEST] Need help with Porygon>Porygon2>Porygon-Z evolution

[Dull Deoxys]

I have an EV-trained and IV-bred Porygon that I want to evolve into Porygon-Z. Here's how I want to do this (mainly for efficiency):

-I trade you my Porygon that is holding an Up-Grade.
-I then trade you a throwaway that is holding a Dubious Disc in exchange for a Pokémon that isn't the Porygon2.
-Once that trade is completed, I will finish the initial trading, allowing you to attach the Dubious Disc to Porygon2.
-You then trade back the Porygon2, this time holding the Dubious Disc.

If you want, I can give you a Salac, Petaya, Lansat, Custap, Enigma, Micle, Kee, or Maranga Berry. I could also give you some spare PP Ups that I got from the Loto Corner or a Rare Candy that my Teddiursa picked up while training this Porygon. I've also got way too many Heart Scales, so I can give you one of those if you'd like.

My FC is to the side, and IGN will be Sempai (icon is the OR/AS male Ace Trainer).

EDIT: Finished! Thanks @FroslasFan14!