The Old Town canoe with serial number 141091 is a 16 foot long, CS grade, Yankee model with red Western cedar planking, open spruce gunwales, ash decks, ash trim, and a keel. It was built between October, 1944 and June, 1945. The original exterior paint color was fire red with a G. S. (Guide's Special) green bottom. It shipped on June 21st, 1945 to Vergennes, Vermont. A scan of this build record can be found by following the link at the attached thumbnail image below.
It is also possible that you could have another number or manufacturer if this description doesn't match your canoe. The serial number that you posted indicated an 18 foot long canoe so you may want to check the number and the length again. Feel free to reply here if you have any other questions.
Thanks, Benson. Without doubt that is the boat. I personally hauled it out of a barn at Basin Harbor Club this afternoon, at the request of the son of AP Beach, so the provenance is pretty clear! (I guess I should have known it was not 18' long, however.)