I'm considering buying a barely-used (2 mags, according to the seller) R9S, serial number R129X. Poking around this forum I found some references to slide cracks and a change to different steel, apparently in the "1100 to 1200 range" according to one post. Anybody have any more specific info on that? And are there any concerns that I should have with a R9S of this vintage? Any special skills/tools required for normal maintenance? I have several nice carry guns--Seecamp, Kel-Tec, Colt Mustang--but I'm hoping that this could be "The One". Thanks! MARK