Sounds a lot like a MK I. I just happened to pick up a MK I that's in almost mint condition (blue), low serial #, says DETONICS .45 , PAT. PENDING. - on the left slide flat. On the right slide flat nothing. ON the right frame says DETONICS ASSOC. and serial # starts I 63## .... from the looking that I've done we both should have variations of the MK I. Is it special? It is to me