Cowboy: I have (I think) the same set of Hogue grips for my Mil (the one piece with finger grooves), they are a bit tricky to put on in the beginning, You basically mount one side (with the screw in), then pull the other side and hold it in place and set the screw, after a while it will stretch enough. I repeat, you have to stretch 'em up a bit, Until the "shelf' (the part inside the grips catches on with the pistol frame, then you have to make sure the magazine brake pin is set properly (all the way in).
Of course the best solution to your situation will be to get a set of Hakan made grips, the will add value to your gun, I trully mean it.
Carlos
P.S Forgot to ask...are you the same Cowboy1 from 1911 RRA forum?