Boatdoc-
I don't think anyone makes prebuilt caps for what you're describing. I think you'll need to either build it yourself or take it to a reputable fiberglass restoration facility.
As far as t-tops are concerned, I can think of two places in New England that make great tops.....J&J in Falmouth, MA and Redman Marine in Saco, Maine. J&J is definitely the more expensive of the two......but Noel Redman of Redman Marine does beautiful work
www.redmanmarinefabricators.com
I think someone from this site had the manufacturer that builds the t-tops for Regulator build one for his 23. I am not sure how he got it up this way from NC though.
goodluck