Well I got it flat eventually. I finally got the part for my router so I resurfaced it with a jig I made a while ago with a nice big flat cutting bit. Then I went to sand it with my Bosch ROS and it promptly died on me. A new one is $145 and repair at least $60 so I bought a cheap Chinese ROS for $50. It wasn't going to do it all so I bought a belt sander. Once all these came into play the board was as flat as I can get it and looking beautiful. As promised elsewhere pics are in alt.binaries.pictures.woodwork.
Thanks for all your help.
Mekon