had though about that, one of my players is a real tinker, most of their gear will be battle field salvage, while building loot tables i tend to include destroyed components (as basic scrap for a scrap dealer) then though about adding sub components to those, eg ammo feeder, barrels, emitters Etc... could add jury rigged rules to these i guess.
I did find a weird build from one of the Solaris jocks, frankenmech rebuilt out of four others, more than likely a Apocryphal note than Cannon.
edit: should add, the players character is also a tinker, grew up around Comstar in the Sol system, managed to learn a few things about how things work, did not drink the comstar koolaid though.