To the OP...
Great Lakes Canvas was the original manufacturer of our canvas and has the patterns.
Unfortunately there was no FULL COVER offered for these boats, especially one to fit an extended platform. I would also be VERY cautious about trying to use canvas as an outdoor winter cover if you get snow where you live. The weight of snow will destry expensive canvas in a hurry.
I have used Great Lakes to replace my entire set of canvas and was 1000% happy with prices, fitment, cost and shipping.