OK, I've swapped Ruger grip frames before, but they were always New Model to New Model. Now I want to swap a stainless Super Dragoon (new model) grip frame onto an Old Army. I know about needing an adapter block for the trigger return spring. Any other issues, or is it a straight forward swap?

I have built the block for the trigger return sprinf from plastic. easier to shape and works great. Everything else should be fine if you use the right hammer. post pics.

Not any options there, I have to use the Old Army hammer.
I wonder if that fits the slot in the SBH grip frame, or if it leaves a gap at the rear.