Maybe someone knows them and were to get a fitting fin? The fin box is relatively special. If not, maybe replacing the whole box is an option. Quick & dirty would be just to press a new fin in and fill everything with epoxy but I would prefer a less destructive option if possible
More like an early 70s board. That is a really odd fin system. While similar to Guidance, Simplex, and even the late version Waveset it is none of them. In fact, I have never seen that type of box before. I would feel confident in saying that you will never find a replacement fin for it. I assume there is no markings in the box so it’s essentially a “no name” thing.
The fin base does not look really complicated and I would try to make a solid glass fin to fit. Second option would be to just take a router to the box and install a new one. The board has little to no collector value so doing a modification won’t be a crime.
Seriously, good advise above. If the box is similar in cut out size to a modern box I would think nothing of routing it out. You might be able to do it so that nobody ever knows it once had a different fin system.
can you show more pics of the fin in the picture, along with a description of whats wrong with it? The original fin, or at least the base / tabs might be salvageable.
I do recognize that fin box,(having seen it before) but for the life of me cannot remember the name of it. It was short lived, in any event. Circa 1969/70. As I recall, it was longer than the FU box.
One of my first jobs was making those bungee leashes with the hogring crimps at each end. I then progressed to making the surgical tubing ones that had cord within them to limit stretch. I made some good extra gas money that allowed me to travel the coast.