I inherited these 90's era boards (in 2006) and want to determine the best fin size, sail size, wind condition parameters to take them back out. I was off at college and never really used or rigged these boards that I recall. I have been windsurfing again since 2017 on an Exocet 11-8 WindSup. I can likely still water start though I'm 30 years older so who knows. I am still learning to foil on a Slingshot Levitator 150 and thought I may try out the old Bics on non foiling days
Also, my web research has not found anything but the board specs and statements without explanation that modern sails are incompatible with vintage boards.

ROCK2,95 m0,60 m9,5 kg130 l[nbsp]race slalomThermo92/95
ELECTRIC ROCK2,65 m0,58 m8 kg102 l[nbsp]slalom MWThermo88/95

Other than trial and error, any fin (with wind range) recommendations for these boards would be appreciated.
That is unless modern sails are incompatible and and this would be a frustrating experience. I'm stubborn and may likely take them out anyway with whatever fins I have before defaulting back to my Exocet.

Thanks