Rub Rail
I have replaced mine twice, not to tough. Try to choose a warm day and let it lay out in the sun to soften up. On really tough spots you can use a heat gun (go easy) or a hair dryer. Place the bottom in the rail, then use a blunt putty knive or large flat screwdriver to push in the top. Once you get the hang of it you will fly. Total time on a Cat 30 around two hours. I did purchase directly from Catalina. The cost in 2005 was $1.76/foot. If you need to replace any of the aluminum channel the cost was $2.08/ft. I do not know if the same part numbers apply to an older Cat 27, but the aluminum channel was #20836, and the rubrail in grey was #20837.