Lipsey's just ordered a special run from Ruger in a "non-cataloged" configuration. Think KMK512, minus 1 1/2" of barrel...
Warranty is handled through Ruger, just like any other MKII.
You'll probably have to get your local dealer to order one special, but I think you'll like it. It's got a great balance, and almost feels like a "snubby" revolver. It's my favorite of all the MKIIs I've shot.
The only problem that I had with mine is that it seemed to take a little longer to "break in" and smooth up. Now that I've got a couple of bricks of HV ammo through it, there's no problems.
BUY ONE!!!