That’s a cool piece of history. Definitely don’t paddle it out without first having it shaped and glassed. Maybe try contacting Joe Bark, Eaton, or another established paddle board shaper. If the name isn’t important I’ve got a buddy in Northern California who shapes beautiful surfboards as well as prone paddle boards and is an accomplished paddler in his own right. He might be able to help or offer advice. Let me know if you want his info.
Alternately, I would imagine that some of the old-school lifeguards might have an appropriate board that you could borrow if you are on a tight timeline. I was a State guard in Huntington back in 2000 before moving north and guarding up there for a bunch of years. I might be able to re-connect with some friends who where there long before that, if you want me to reach out.