As a follow-up, I found a local canvas shop at Smith Mountain Lake and had a three-foot zipper installed at the bow of the boat. Virginia Canvas did a great job, the zipper matched the original located on the port side. Finally able to get in without going to my knees.
What did that cost? I might see how it compares locally to do the same. Might actually have the side one replaced as it is a narrow one and I’ve seen some covers with a larger one. I’d like a flap to cover it also to protect it from the sun.