Sorry to report that knowing exactly when your Penn Yan was built won't be possible unless a previous owner helps you with that. There are no existing records for Penn Yan's boats, which would allow us to connect your serial number to a build record. The serial number tells us the canoe is a Hunter model, which you already know. But, it may be possible to narrow things down by looking at the canoe.
Penn Yan built the Hunter model from 1933-1960. Apparently, in the second-half of any given decade, the first two digits of a Penn Yan serial number indicate the year it was built. This doesn't work for your canoe, so we can assume it was built the first half of whatever decade... which would be early '30s, early '40s, or early '50s.
If the canoe has war-era seats (plywood inset into the place where cane should be) or other aspects of construction indicating it was built when canoe builders couldn't get copper, brass, or cane, then it could be an early-to-mid '40s canoe.
I'm using information at www.dragonflycanoe.com/id/ as a reference, if you want to check that out (scroll to "Penn Yan" on the left).
If you post pictures, maybe someone else here has a thought. With most canoes by the old companies, there is no way to date them precisely... we have to go by clues based on the canoe itself-- sometimes a decal-type or change in construction or another detail. Someone else here may have a canoe similar to yours, but with paperwork or verbal history.
hey Canoe Nut
Not sure if I understand Penn Yan's numbering system but I have hull number CL-859. It is either the year after yours or the next boat built. I also have a PY guide boat and it is a thing of beauty on the water.
I too have a Penn Yan Hunter Canoe that I have had since childhood. My serial number is CL 855 and I too would like to know when it was built. My dad bought it for he and I ( in the very early 60"s or late 50"s)and he has long since passed away so I do not have his purchase records. I know he bought it new when we lived in Geneva, New York. I would like to know more about how to interpret the serial number. The canoe is in great shape, I am very careful with it because of the memories of paddling the Fulton Chain many times with my dad as a boy. I have paddled a Mad River Special Edition Explorer for years because I do not want our grand kids to damage the Hunter.