Chig's Grips does a great job at custom grips and they don't break the bank. He will make them custom fit to your grip frame or fit to one of his. You can pick the wood blank from his website and the cost includes the fitting.
Well used doesn't necessarily mean it was fired a lot. If you don't have reason to believe something is wrong with it, I wouldn't send it in. Hopefully, in that condition you got a really good deal on it (like new ones are selling dirt cheap right now). I like the worn look, it adds character.
I bought this SBH a few months ago just for the grips too. I got it for an awesome deal even if it hadn’t had the stags. I didn’t need another 44 but I couldn’t pass it up.
The original Pachmayr "Presentation" grips for a Redhawk are very large. I have large hands (2xl gloves) and they are almost too big for my hands. I can just reach the trigger with the tip of my index finger (double action mode)