I believe it's 1974... Bought new by my dad. At the time he was a dist. for Sabb diesels which it makes sense to me why there's a Sabb diesel in it. The hull is red. I do have pics but haven't figured out how to upload them in this thread. I do have the mast and original sail, even have the original seats (ugliest red I've ever seen). I'm not sure what the hull number is but the bronze plate ID has a #15 stamped in the middle and Herreshoff Pilot. There are numbers imprinted on the back lower part of the hull that is similar to a vehicle vin number, but haven't wrote those down yet.
I really appreciate any help you could give.