I have a 1983 Catalina 30TR with the "no longer available" black plastic deck fill caps. They were make by wilcox critteden and are stamped 1 1/2 " WC on the inside. I do not which to change all the four assemblies which require new drilling and bedding. I have tried 4 local marine supply houses, WC, Defender, Catalina Direct, Catalina parts (which hasn't responded) and am ready to give up. Does anyone know a source?