What ever you do try to remove the bulkhead in one or two pieces that can be put back together for a template! making a new bulkhead without a template can be a royal PITA!!
I would not personally scarf this project and your on the right track with replacing the whole thing.. If you are not a stickler on having a teak face to the marine ply it will save you LOTS of money. Simply paint the new bulkhead white and go for a Herreshoff look. It would also brighten up and make the 28's cabin feel bigger.
This is what is referred to as a Herreschoff look..