I have been waiting to see if someone had a plan that wouldn't require altering the pistol. I believe your Cimarron was made by Uberti, and shares a common frame with my Uberti pocket police.
I was having the same difficulty capping, that you describe. What I did, was put a small grinding wheel in a Dremel tool, and ground a notch into the frame, similar to the one on the 1860 Army. I quit at the right depth, so that a cap lays in it, and can be pushed on with a piece of 1/4 inch dowel pin. After cutting the new mortice, I polished it, and using a Q tip, applied just enough cold blue to discolor the bright metal to match the case color near it. Looks like it belongs there, and made capping much easier.