I 've had some canvas work done a couple times at Atlantic Coast Canvas in Scituate and the guy was very good as well as reasonably priced. He's at the marina at James Landing on the Driftway in Scituate. When you walk into the building, the sales offices are on your right. He has a set of stairs next to those offices leading up to his shop.
I've also known people that have dealt with Poor Mann's Canvas in Weymouth. If memory serves me correctly, they are in East Weymouth in or around Jackson Square.
There is also Building 21 Boat Tops in Rockland. Used to be at the Hingham Shipyard but now on Union St. in Rockland. I asked him for a price on something before and felt he was a bit high in the estimate. Wouldn't hurt to get a price comparison though.
