I used to have a "Liquid Metal" tube glue, that kind of smelled like epoxy, but was a 1 part adhesive. It was sold for hardware work, and I think it was a metal filled aliphatic resin type of glue, or something along that line. I don't know if you can still get it or not. I remember it being called Liquid solder by one manufacturer. That worked really well on photo etch. I used to use it on photoetch body work on race cars, and file and blend it right into the rest of the body work. We would use photoetch pieces for the spoilers, and the edges of the bodies, to make them look thinner than plastic. THis adhesive would blend it right into the plastic, ,and still remain workable with small hand tools. It also filled, and took paint well, and didn't shrink. It looked almost like mercury or something. Maybe that's why I haven't seen it recently. I'll check out the hardware shops this week, and see if they still have the stuff, and try to get you a brand name.