Wandered arounded the local Gander Mountain g to see what they had for used guns; and came away with a MagnaPorted Ruger GP100; 6" Blued, re-crowned muzzle, and trigger work...$349 plus tax.
Looks like the Pachmayr Gripper is being stresed by the alloy plug. I use those grips on mine, sans the plug.
I think you got an excellent deal, although I prefer stainless guns. That should be an exceptional range and woods gun, where open carry is legal.
Let us know how it shoots. Pity about the porting, which will be hard to keep clean and lose velocity. The gun is probably louder than a non-ported one, too.