I have the same gun, and the same problem. I purchased the Pachmayr grips when I carried this as a backup gun for many years. For concealed carry I went with Tyler T- Grips.
An aluminum piece that slides in between the wood grips behind the trigger guard. They are not rubber but they do fill your hand a bit more and don't add to the bulk of the gun like the rubber grips do.
I would also be interested to see if anyone else has some better ideas.