A couple issues with the character:

-People living in the Undercity are basically not allowed onto the surface, and none of the area is anything like a post apocalyptic area where one would be doing the kind of salvaging described here, broken androids, especially combat ones, would be scrapped and replaced, not left to rust.
-The micro torch in his finger is a bit small for the tech levels available. Cybernetics have the vast majority of their space taken up by the pieces needed to move them, and there simply wouldn't be the space necessary for even an incredibly small addon without the cybernetic being very expensive and specialized (something that does not seem to apply to 4's cybernetics.)
-AI chip seems rather unnecessary without a description as to why it's there, as is it just seems like an excuse for extra augments.
-Tracking device is, frankly, rather OP.
-A character described as cautious due to the event that gained him his first cybernetic doesn't strike me as the type to graft more robot parts on just because.