Moved this out of the pip boy discussion so maybe it gets more views.

Well, just a crazy idea but...
Heavy has an identical primary replacement, Snipers got a few rifle replacements, Soldier's got a primary replacement, and Spy's got a few knife replacements, not just the standard knife either.

Lets say they made this a PDA slot. It doesnt look like it'd interfere with many jackets/chest mods, immediately. There hasn't been a ton of high-tech-ish engie bits that match the TF2 general design like this. Valve is kinda picky from my understanding about making sure items don't go too overboard, and this plate metal plus just the hud isn't flashy. It seems like it may get picked up, and could start a great theme for items-to-come to follow. Also, I haven't looked so I don't know if there are some already on the workshop, but why not pair this up with a sentry revamp? About time the sentry got some love damn it.

Some people with skillz contact Jukebox and:
-make a simple transparent HUD that matches his design, for the player's normal HUD and the PDA.
-Change the PDA stance so the screen brightness or images change, instead of his hands going up.
-Sentry redo

This would sell for billions of buds. I'd pay.