the only one i know of is on the west coast C-Fab in so ca they do very good work , i will bet some of the east coast guys will know. good luck travler
There is a place in Fort Lauderdale by Westport yacht brokers. I looked at some of there tops and they did a great job. Lots of options like flip down TVs, front lights, rear lights, Etc. They seem a little expensive, or maybe I am a little conservative. Call Claude at Westport and he will be able to give you the name. Tell him Scott (purchase a Westship from him) sent you.
J And J Marine Group Somerset Ma. They do a great job and are very detail oriented. Very good at custom work.
Thats the place. I kept thinking pipe fitters but Ken is right its Pipewelders. I still might get my hardtop there on the way back down.