Yeah I did the same for awhile search for Dominic Nataro grip mod, I think his handle is tech teach he has a website too
He makes a grip that goes over the non RP grips, there is a video showing how to drill them in, using the plastic to screw to. Personally I would rather have a bushing as the plastic would eventually wear out IMO. There is another way by using 3m double stick automotive tape. (its what they put those annoying dealer decals on with) that's the method I'm going to use just waiting on them to come in. I believe they are $26
He makes a grip that goes over the non RP grips, there is a video showing how to drill them in, using the plastic to screw to. Personally I would rather have a bushing as the plastic would eventually wear out IMO. There is another way by using 3m double stick automotive tape. (its what they put those annoying dealer decals on with) that's the method I'm going to use just waiting on them to come in. I believe they are $26