Thanks Hermco, that makes it a little easier. Removed a portion of the transom today. It's like opening up a time capsul, haha. I found two copper ring nails through the transom with the head just inside the inner skin facing out. May have held a template or something. Also confirmed a 4 stringer hull.
See Pics The filler in the gaps at the strakes between the plywood and strakes is like a sawdust and glue mixture, weird stuff.