Congratulations, Greg. The 20 footer is rare... for most of Morris's production years, they only offered the 20 footer in Model A. Then it appears in the catalogs after 1915 as available in both model A and B (but never C or D). Morris didn't make a war canoe, so this was their longest model.
The longest, widest Morris I've seen is the special-order one in the storage facility of the museum in Blue Mountain Lake-- an 18 1/2 footer fitted for rowing and sailing.
Interesting that your canoe still has its middle thwart!
Nice find.
Kathy