I have a Cobra upper that fits the GT-40. Some foo who shall remain nameless (heh-heh-heh-heh) got a throttle cable stuck under it when mounting it onto the lower and it broke off the mounting tab right through the right rear bolt hole. Yes that guy was a major foo! No damage elsewhere. Just needs the outer half of the hole welded back on. Easy fix, i just never got around to it. It's been cluttering up my garage for a year or so. Cheap if you want it.