Gentlefolk, New to this forum and to Glocks, so I am seeking more learned opinions. I was waiting for an NYPD-used 23 to come into my dealer. Delays mounted, NYC would not ship them. Finally found what I thought was a decent deal on Gunbroker for a Gen4 23. So I got that. of course the next day the dealer called and sd the NYPD Glocks had come in. Since I had essentially promised to buy one, well, I ended up with a very clean Gen3 23. So now I have a Gen 3 and an as-yet unfired but cleaned Gen4 23. My question then...do I keep both, trade one for something else, if so what, and how much value have I taken off the Gen4 by cleaning and fitting a backstrap, but not yet fired? Many thanks for any thoughts.