Steve,
I have two Morris canoes, both with floor racks. The rack on my 16' Model A, Type 1 is 130" long, six spruce strips, each 3/4" wide and about 1/4" thick. All the strips are the same length, cut square on the ends. The rack is 10 1/2" wide in the center, 8" wide at the ends. There are four cross pieces made of hardwood. The two at the ends will need to be steamed and bent to fit the curve of the hull. They are about 1/4" longer on each end than the rack is wide. The strips are attached to the cross pieces with brass escutcheon nails rudely bent over under the cross piece. The little blocks for the toggles are also hardwood. The toggle, made of a piece of stem band is held on with an escutcheon nail again rudely bent over on the bottom. (A brass screw like Old Town used would have been a better way of doing) Two brass flathead screws secure the blocks to the rib.
On my 17' Model A, Type 3 (24" decks with coaming) the rack is 142" long and it has five cross pieces. It's a foot longer than the other canoe which is logical given that the canoe is a foot longer.
I expect that there is a bit of variation in the racks depending on who was putting it together that day.
Good luck with the restoration.
Jim