Managed to get a late 80s Mistral comp light for ?20, (surprisingly light compared to my old club version) and have only the board and fin, so will need to make a centreboard, and bodge on a chinook mast base ( should be ok, as the bolts line up with the 2 mast foot holes and can bolt it on with long bolts accessed from below) . So, was thinking that as i will be sailing with a modern rig possibly a 5.5 m ks3, so making the C of E further back. I might make a thinner centreboard and bigger fin, to either fit in the existing swivel mechanism, or glass in a new fin box.
My question is, does anybody know what i'm likely to find construction wise if i rout out the old fin box? and has anyone modified such an old board successfully?