Freesail, wherever possible I will be using the existing tracks originally provided in the boat. The forward bulkhead will be bolted into these tracks like the original. The new aft bulkhead will be bolted in at the bottom where the cabinet was bolted into the sole track. Otherwise I will use epoxy and tape to tab the bulkheads in.
Except for where the aft bulkhead butts up against the compression post I will be putting a thin layer of weatherstripping to isolate bulkhead from hull. The forward bulkhead had this, even inside the tracks, so will repeat this. I have also read many times this is important to not create a hard spot in the hull.
My hope is that when done I will have a much more comfortable head and a stronger boat overall. The forward bulkhead will now not be rotten and the aft bulkhead will be new and provide added support.
You will regret the things you did not do, more than the things you did.
Get out there!
Saco Bay, Maine
2001 Beneteau Oceanis 361