What you might use is a remodel escucheon aka remodel plate. I know that both Delta and Moen make them and I wouldnt be at all surprised if Price Pfister does too. I dont carry PP so I cant say for sure. I've installed the Delta remodel plates on American Standard tub/shower faucets and it looked great. In addition there are generic remodel plates out there. You'll find any of these at most plumbing supply houses.