Add another MR1 owner to the page... Is it common for the rear sight to be missing? I bought mine used as well. At least I didn't pay much, a bunch of old boxed Aluminum cased 9mm, some old .40 and came with it and ~$100. I still haven't fired it yet, it's been laying around for at least six months, looks interesting but range time has been a bit rare lately. I still haven't tossed an optic on it, can't decide if I'll go magnified/electro/red dot.