I live down the road from you in wellfleet, and have driven past with a bracket'ed 77 23 in tow a few times. I have my bulkhead out in 2 pieces, and will be using it as a template, so if you cant get yours out in good shape you have backup. i will be doing the 3/4" pvc approach. winter project
. my bulkhead was not bonded to the cap and provided no structural beni that i could see, had 2 screws holding it in place on inside corners,some calking, and I saw-zalled it out in 2 pieces. add a couple foot stomp beat downs and it popped pretty clean-nuff to use as a template. would have never replaced it but went to re-wire the bow light and my weight crumbled the bulkhead bottom under door area, only thing holding it together on bottom edge was awlgrip.
i can look up where i sourced the 3/4" pvc if you want...it was a pain in the butt, first company shipped me 3/4" starboard and i was pissed and had to eat frieght on their mistake.