I recently came up fruitless in my search for a fixed sight, 3" GP100 at my local gun shops. I did get the chance to handle a new Colt King Cobra, however, and I was pleasantly surprised with how much I liked it. It balanced well in the hand, the trigger was excellent, and its fit and finish were stellar. I do wish the topstrap gutter sight channel was a little deeper, and I'm still not a fan of the squared-off trigger guard, but those nitpicks were minor grievances at best.
One thing I couldn't get over was how much I disliked the Hogue Monogrip though. The rubber was uncomfortably hard, and I generally despise the stippling pattern Hogue uses and overall shape of these things. For a gun so close to the $1000 price point you think Colt could've sprung for something a bit better. I came home with one of the King Cobras I looked at - the deciding factor was that I heard D-frame Pachmayr grips would fit. Specifically the old Colt variety with the lovely gold or silver Colt medallions in them.
Upon receipt of the new grips in question from Ebay, I was incredibly pleased. These old grips improve the silhouette of the gun tenfold, and the checkering and medallions match nicely with the semi-polished finish to give the entire thing more of a premium look. (Well, as premium as a rubber grip can be.

) The softer rubber of the Pachmayr/Colts felt much nicer to me as well. I did run into two concerns, however. There was a slight wiggle to the grips against the frame, and the front edges of the grips didn't meet.
I mitigated the first issue by using some electrical tape to increase the diameter of the shaft of the grip screw. This presumably helped anchor the grip in place since these new King Cobras don't come with the standard D-frame stock pin, and vintage D-frame pins seem to be impossible to find. I'm hoping the tape will hold up under shooting, and I'd be open to hearing alternatives if anyone has suggestions.
The second concern was the primary inspiration for this thread. Modern one-piece Pachmayrs were never known for having the greatest fit in the front, but apparently the new King Cobra's grip frame is decently thicker than the old D-frame guns. (Why would Colt have ever considered existing grip inventories and manufacturers when crafting a new piece that's fairly close to its predecessors?

) Is there a preferred method for trimming the inside of a Pachmayr grip, or is an X-acto knife and a steady hand the best method? Is any sanding necessary? Is there a good way to tell what sections of the grip interior have to be trimmed? And is it better to freeze the grip prior to cutting it?