If this canoe was built on a form, I'm guessing the form fell off the second story factory balcony and the form was used as is. Or it was built without a form in a back yard in an attempt to copy a production canoe. Whatever it was I'm stuck with it and would like to finish it, so maybe use all three options and live with it.
I thought about not using the keel but it's 18' with a 41" beam square stern and I thought it would be best to use the keel for strength. It will be used to haul a lot of outdoor gear plus three adults.