Ends resemble an OT Molitor, stem stamped 308 33 17 and the deck plates aren't OT, and possibly not original . Original owner sold it in 1970 and said it was new in 1919. Any guesses as to builder?
I agree with Dan that it is probably a Robertson. There may be a stamp on the top of the thwarts along the gunwale. The page at https://wcha.org/classified-archive/Robertson.html has some similar examples from the classified archives.