Heh, shows what I know.
I'll buy a tension gauge and see if I can't find a local expert to help me out with this. I don't really know anyone suitable, maybe I'll hire someone.
Determining the "usual" rig tensioning for my boat is going to be very difficult if not impossible. There aren't very many of these boats out there. Although my tensioning might need to be similar to other models by the same shipyard, but I would sort of doubt that since the other models this size have completely different rigging.