Never heard of Green Stuff. I got a car fix that might need JB ClearWeld, I dunno yet. For plastics, Cyanoacrylate accelerant is like standard now, used it once so far, wow, I'm sold. Henckels and Bob Smith Industries makes it. I can also recommend Plastic Wood by DAP, solid. Great little filler. Heres a trick I figured out if youre low on CA or Threadlocker: Gluing one screw of multiple on a plane, like on a door hinge or handle, is sufficient, instead of all of them. The glued one "holds down the fort" to keep the others from vibration loosening. So you can be quicker and economical, and give yourself easier part disassembly for future replacement. Another trick: Drop of oil/lube on glue cap screw threads, prevents them from sticking shut.