Thank you all for your input. This helps a lot.
I have a 41 Mag New Blackhawk and the grip frame parts from a Cimarron Arms Thunderer which I would like to fit to it. I don't mind welding up and redrilling a hole or two if that's what it takes.
Unfortunately I am not in the US right now and can't check this out for myself. I guess this will wait until I get back.