We are making headway guys and gals !
In an article about the Tornado the F16 boat are mentioned.
TheDailySail.com article in proof read version And I quote :
"As mentioned the Tornado was born of the B Class Catamaran rule, one of four very rudimentary box rules created by the IYRU in the early 1960s – perhaps the earliest incarnation of what now exist as the Formula 16, 18 and catamaran rules ..."