Has anyone tried using the rough rubber tape-on grip panels on the P-64? I was a modeler years ago, and don't know if I would attempt it now. But, it wouldn't be that hard to slightly recess and smooth the checkered area on the panels with a Dremel and trim edges with an Exacto. Then trim the rubber panel to fit and tape/glue it on within the recess.
This adaptation would greatly improve and soften the grip while not adding any width or weight to the gun. I think it is a good idea but don't have an extra set of grips to play with!! :-/