Surfing Waves

Hi all,
I’m looking for fins for an old circle one board.
It’s 6’3” and has a single slot fin box with screws on the sides.
Please help! It’s my teenage board and I want to get it back in the water!
Please see pic of fin box attached.

Looks like Jaffa solved this one at the link below. I've used FCS fins without any issues on DFS boxes.. Futures were hit or miss

viewtopic.php?f=20&t=34267