It is mesa tactical. It is a six shot side saddle/rail combo. Just side saddle or just rail options are available. I got it from Brownells, can also be had from GP Tactical, a good bunch. The rail is cool because there is a space underneath to use the bead sight if desired.
I love the urbino stock, it completely changes the feel of the gun. So much easier to reload with the pistol grip, the adjustable cheek piece is quick to adjust and very sturdy, and the limbsaver has a very notable reduction in felt recoil. Of course you know all that, just want to share the info with anyone curious.