Almost any wood canoe is worth reparing. If you don't have the time or interest than let it go to someone who does. There is a good summary of how to value and sell an old canoe at http://forums.wcha.org/showthread.php?t=57
in the FAQ.
The Old Town canoe with serial number 142035 is a 20 foot long, GS grade, Guide's model with Western red cedar planking, open spruce gunwales, ash decks, ash trim, half ribs, a keel, and a motor thwart. It was built between April and June, 1945. The original exterior paint color was G. S. (Guide's Special) green. It shipped on June 22nd, 1945 to Rockwood, Maine.
The Old Town canoe with serial number 42035 is a 16 foot long, CS grade, HW (Heavy Water) model with Western red cedar planking, closed spruce gunwales, ash decks, ash trim, and a keel. It was built between February and April, 1916. The original exterior paint color was dark green. It shipped on June 54th, 1916 to Paul Smith's, New York.
Scans of these build records can be found by following the links at the thumbnail images attached below. These scans were created with substantial grants from the Wooden Canoe Heritage Association (WCHA) and others. Additional information about the project to preserve these records is available at http://www.wcha.org/catalogs/old-town/records/
if you want more details. I hope that you will join or contribute to the WCHA so that services like this can continue. See http://www.wcha.org/wcha/
to learn more about the WCHA and http://www.wcha.org/join.html
It is also possible that you could have another number or manufacturer if these descriptions don't match your canoe. Feel free to reply here if you have any other questions.