The Old Town canoe with serial number 184743 is 17 foot long Molitor model with a keel. It was built between March, 1970 and February, 1971 . The original exterior paint color was similar to the image at
http://www.wcha.org/catalogs/old-town/designs/design45.gif which was known as the design number 45. It shipped on February 19th, 1971 to Jackson, Michigan.
The Old Town canoe with serial number 184597 is a 15 foot long lightweight model with a keel. It was built between February and March, 1970. The original exterior paint color was red. It shipped on March 21st, 1972 to Jackson, Michigan.
Scans showing both of these build records can be found below. These scans and several hundred thousand more were created with substantial grants from the Wooden Canoe Heritage Association (WCHA) and others as you probably know well. A description of the project to preserve these records is available at
http://www.wcha.org/catalogs/old-town/records/ if you want more details. Your life membership is much appreciated.
It is also possible that you could have another number or manufacturer these descriptions don't match the canoes. Feel free to reply here if you have any other questions.
Benson