Any advice on restoration of a old Parrish single fin

Can anybody forward me some advice on how to remove a twist ( nose to tail ) on a old Parish single fin.

I’m going to remove all glass as this needs doing. The board has two stringers running from nose to tail, that increase out as they head towards the tail.

 

Was thinking of using weights hanging down some way. Would reglassing hold the twist out. 

 

Regards Keith.