I wrote up a very similar board, which is incidentally still for sale here. The board pictured here, though, is the same price ($400), and it looks to be in much better condition. It has the original fin, which has apparently been bent from storage, but according to the posting, it can be clamped back into its original position.
Dims are 7′7″ x 19 1/2″ x 3″. What’s not to like about vintage Hawaiian single fins? Check out the board here.