Good info, however I've found that a few different companies make the canvas. It all depends on your model and the year (as I suspect their suppliers change from time to time)... As an example, my 1875 Crossover has Dowco canvas and I think I've seen at least one other brand of supplier.
As an additional option for folks, check out greatlakesskipper.com . Their stock rotates often, but I found "sport tops" for my boat there for a fraction of the dealer prices. They have lots of other accessories as well.
Edit for you, copperpin:
http://greatlakesskipper.com/lund-16-17-18-predator-1825-rebel-gray-boat-snap-in-side-curtains-1997368-set-of-2