Welcome, the Old Town with serial number 183825 is an 18 foot long Guide model with half ribs and no keel. It was built between September, 1969 and January, 1971. The original exterior paint color was dark green. It shipped on February, 12th, 1971 to Bangor, Maine. A scan showing this build record can be found below.
This scan and several hundred thousand more were created with substantial grants from the Wooden Canoe Heritage Association (WCHA) and others. 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. I hope that you will donate, join, or renew your membership to the WCHA so that services like this can continue. See https://www.woodencanoe.org/about to learn more about the WCHA and https://www.woodencanoe.org/shop to donate or join.
It is also possible that you could have another number or manufacturer if this description doesn't match the canoe. Page 11 of the 1971 Old Town catalog at the link below has more details. Feel free to reply below if you have any other questions.