I'll just put the Pics in for now an put up a bit of an explanation later.
You should be able to see whats going on so far.
Edit. It's 11.39 and I have a few surfboard making things inn the go in and around jobs and I can't sleep so the quick explanation First shot is obviously the mega rough of the blank after stripping. I used the section from just in front of the water damaged stringer.
The next couple show the blank before and after cleaned the bulk of the discolored foam with the planer and worked out the twist with a 23 inch piece of timber with 40 grit glued to it combined with a builders spirit level. Then after final outline squaring and the beginnings of rocker enhancement.