I don't think you can do anything with the Grips of the 22/45, as I think it is a polymer frame gun with integral grips. (Perhaps I'm wrong, and the grip panels can be removed...) But even if they can be removed, I've never seen replacement grips.
You can use the Hogue (or comparable) handall slip on grips, but that's not really much of a solution if you're looking for new grips.