First, a minus for the fact that the seller does not specify the color of the frame they send (mine was blue, I would have preferred black). Besides that, the frame required sanding the paint from the bearing holes, as the bearings would not fit. The piston and feeder guides also had to be cleaned of paint and then sanded with a Dremel to remove casting defects and polished, as they were too rough from the factory. Maybe this was a one-off case, but I needed a screwdriver with a sanding tip for the holes, a Dremel with files, felt, and polishing paste. Also, the selector plate in the AK did not engage with the fire mode mechanism and also required modifications. After 4 days, I managed to assemble the gearbox, so far it hasn't fallen apart from the M135 and works.
