Need help identifying the age of my Grumman canoe

Hello all.

Can someone help me identify the age of my Grumman canoe? I read they sometimes have a HID located near the stern of the boat but I have been unable to find it.
I have also emailed the marathon Boat Co but have not heard back from them yet.
It is a 17’ square back.

Please click here for photos.


May very well be pre HIN number days
Think they started using them in 72
This plate looks exactly like my 68 Grumman

Thanks! Does yours say Marathon NY?

I don’t have it anymore but yes it was made in Marathon NY