The guy who resurfaced our household counter tops and shower surround recently also does quite a few bath/shower repairs for RVs, so he said. You may want to talk to somebody who does this type of thing near you. They can probably make it match pretty good.
Mike, Kim, and Pepper
(Min Pin security)
Current TT: 2012 Eagle Super Lite 308RETS
Current Hitch: Equal-i-zer 1400/14K
Current TV: 2010 Chevy 2500HD, CC, LB, Duramax/Allison