Drywall screws are pretty good, too. Those pointy ends sticking through on the inside will help hold you into the boat in a capsize.... Lovely find, by the way. Enjoy it and don't let the other members drool all over it as it's hard on the varnish.
I actually owned one of the Indian Brand canoes. It was my first canoe purchase, back when I was 16 years old. The line consisted of several rather boxy and somewhat uninspiring, flat-bottomed fiberglass canoes (15' Squaw, 18' Chief and I think there was a 13' model called the Papoose) Then there was the 17' Princess, which I owned and it was a totally different design with the higher ends and a keelless arched bottom (shown with the fake birch pattern on the catalog cover). It was actually a very nice boat in the water and I've always wondered who designed it? The glass layup was rather heavy and primitive with a lot of mat used over some sort of metal rib cores, but it was flexible enough to really take a pounding in shallow rivers. I don't think I've ever owned a glass whitewater boat that was any more durable at any price point.
Stems came covered with heavy vinyl bang strips, thwarts and seats were rigid vinyl and the gunwales were aluminum with vinyl covers to keep the noise down. It was a good enough canoe that if I could buy it back today as a general-purpose beater, I probably would. The line also included either the first, or one of the first Royalex boats, which was a 16 footer and pretty decent for Royalex, but I can't quite pull the model name out of my memory banks.
The company was Rivers and Gilman Molded Products in Maine and after it closed, Mr. Gilman went to work for a little canoe company named Old Town and was a major factor in much of their subsequent plastic boat technology.
Wisconsin River circa 1970-71