Ahhh... the old days....

The (Mares?) fins in the middle would qualify as post-Jacques Mayol, whom I associate with long-bladed natural-rubber Cressi Rondines. Mayol's last deep dive was in 1983, I believe, when composite fins, like the ones in the centre of the picture, with thermoplastic elastomer foot pockets and plastic blades first were beginning to appear.

As for the fins with the reinforced blades, it's hard to tell from the picture what they're made of. If the foot pockets are constructed from natural or neoprene rubber, then it's possible they might date from an era earlier than the 1980s. I've a Fédération française d'études et de sports sous-marins French booklet from the 1960s or 1970s, "Guide de l'entraîneur en nage avec palmes" explaining how to make bifins and monofins with open heels and reinforced blades by cutting up a pair of full-foot rubber fins and gluing everything on to an epoxy blade.

So I need more clues. Are the foot pockets made of proper rubber (not soft plastic)? Is there a manufacturer's logo or at least some indication of the country of manufacture?