J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Mainsail cover

Try Neil Thurston at Thurston canvas in Bristol, RI. Neil does a lot of the canvas work for J/Boats. Web site http://www.thurstonsails.com/Canvas.html
Phone: 401-254-0970
I don't know if he has an off-the-shelf one, but my Sunbrella cover was made by Neil years ago and is still in good shape.