OK, I confess, when I really need to work on a pic, I tend to rebuild it out of spare parts, especially since the Supers (modern, future, whatever) packs I’m mainly using are still kind if a hassle since they untoggle much of the other packs 😉
So basically, I found it easier to do it the hard way : transparent background on that specific piece of equipment, export in photoshop or GIMP, and edit over there. 🙂