Hi Bill,
The Otca has been one of Old Town's most popular models for about 100 years. The design changed in 1957, but prior to that time the Otca had the longer deck that is seen on your canoe. I'll attach the page describing the Otca from the 1940 Old Town catalog, courtesy "The Complete Old Town Canoe Company Catalog Collection, 1901- 1993", available on CD from
http://www.wcha.org/catalog/ and
http://www.dragonflycanoe.com/cdrom.htm on the web.
You can use the "search" function at the top of this page to find old discussions of the Otca... just type "otca" into the little box. I know you want floor rack information too, but typing "floor rack" in the search box will bring up every build record mentioning a floor rack and not necessarily a picture of one.
If there is a wooden thing that looks like a garden trellis on the floor of your canoe, and you can twist a couple turn-buckles and remove it, that's your floor rack. If it's gone, your canoe is like most canoes its age... I think it must be pretty rare to have an intact floor rack in an old canoe. They get stepped on and cracked and used for the campfire... they get removed and left behind on the beach.
You may still see a couple pieces of metal on the floor of the canoe that were used to hold the floor rack in place. Often, these turnbuckles were made from pieces of stem band. Or even kitchen cabinet hardware. Canoe builders were imaginative folks.
The purpose of the floor rack was to keep stuff off the floor of the canoe, which might be damp. Maybe to even-out the floor too. They aren't as hard to replicate as other canoe-related stuff... but each builder had their own design and some people here can say, "that's an Old Town floor rack!".
Maybe someone will post a picture of an Old Town floor rack... meanwhile, I'll look through my pictures!
Welcome!
Kathy