This might be a tough one. The serial numbers don't have a font at all (and thus not from any period in Old Town's history); they look like they were carved by hand at some point, and the canoe has had a variety of other modifications. The seats appear to be reproductions (their components have a plainer shape than was used by Old Town in the early days and they are joined with screws that are capped with bungs - not an Old Town method). The seat bolts are not what you'd find on Old Town, and I suspect even the gunwales might be replacements - the inwales look like they may be maple. The thwarts may be replacements too. The brass Old Town nameplate is from much later in the company's history.This build record doesn't show half ribs, but they look original.
I think you could have a fairly early Old Town given what look like un-tapered ribs. I'll be that with all the other work done, the stems were replaced, and the person who worked on the canoe carved the numbers into the stems by hand. Again, the two "4"s are very different from each other. The "7" has rounded points - this and together with other digits having good points would be very odd in a stamped canoe serial number. The "5" looks like its bottom was corrected after an initial try. This is simply not a font of any kind - there is no cohesive style among the digits. And overall, the stems and serial numbers look way too "clean" for a canoe that has been well used (compare to the ribs and planking... note all that some ribs appear to have been replaced but most are old and well-worn). About the number itself, very often serial numbers on old canoes are read incorrectly so these could have been transcribed incorrectly by the previous restorer when putting new stems in the canoe.
All this said, it looks like you have a solid, useable wooden canoe. If I were you, I'd happily use it. This appears to be a mystery canoe. Maybe there is additional information out there from the person who owned it before you?