My buddy brought an A1 or T90 body to me years ago with a 3rd party extension tube or teleconvertor stuck to it. I recall dismantling it as far as I could to no avail and that it was either a hacksaw or a dremel with a cut-off tool that finally got it done. Should also mention that I stuffed a clean soft cloth down the lens mount opening to keep all the chips from flying into the mirror chamber and shutter.