I just stumbled on this thread and had to pop in.

I have a 645 that I bought in the MCX at 29 Palms back in 1986 or so. It was one of the first ones with a serial number of TAY07xx. I had to have it after I saw a write-up in Guns&Ammo or something like that.

You are absolutely correct about being a fantastic weapon. It eats anything you put in it to include and empty casing. (They said that is the magazine so I had to try it of course).

I took mine apart when I got it and used a Dremel tool and jeweler's rouge to polish any surface that showed marks from wear right after I got it. The trigger resets within 1/32" and shooting double taps with it are incredibly fast.

Out of all of my handguns, it is still my favorite and if SHTF, it will be the one with me to the end.