I agree that MGMAGIC is a good source. I considered them for a long time, but I decided to go to a marine upholstery/canvas shop because of their extensive variety of material. However, I live near Lake Erie which has a huge base of suppliers. Also, this time of the year is a busy time. Cost was in the same ballpark as MGMAGIC, I waited about 3 months, but feel I ended up with a top like I wanted it.
The MG Magic parts are perfect for old CMCs and Fiberfabs, but the BCW is a little different. The front windshield bow is a different design (a block of hardwood), the connection is different—pins from the windshield frame and thumbscrews in the top—and I suspect the dimensions are a little different.
Any good boat place can make the two-bow frame. It’s much like a bimini top.
I can send you pics and detailed description of the rest.