RichH, thanks for all the input and ideas. Fortunately for me, I was able to get the old bulkhead out virtually intact. Only a small section (that which was tabbed to the hull) came out separately but I was able to fit the pieces together for a template. After cutting the new bulkhead, all I could think about was your statement..."You're NOT going to get a new one-piece bulkhead into a P26 or other similar Pearson bulkhead into the flange configuration."
I tried fitting the one piece into place and began to think you were right. Then I had a thought...what if I remove the forward bilge cover? Bingo! The new bulkhead slipped right into place. Here it is.
As for the repair of the compression posts, I decided to make brand new ones out of white oak. They are done, stained and varnished. I also peeled off the old veneer from the header beam and re-veneered with oak. It also is stained and varnished. I'm looking forward to getting things back together. I'll post pics when done.