It sounds like you are talking about the dragoon style trigger guard on the Super Blackhawk, couldn't be sure. If you are, its a cast steel frame. Here is a photo of one I modified many years ago and it was so easy on the hand. Afraid it calls for cutting and welding. I did this 40 years ago, so I used silver solder. Today I would probably choose TIG.
If you don't like Robert E. Lee, you won't like it on this ranch. JGM
