I would get the wood glue and run/force it down between the plys, then clamp it with a few clamps to keep the curve, let dry for a couple of days. It looks like somebody already used Tung Oil on the shell, so put some more on it, let it sit for a bit, and wipe it off. I think that it looks pretty cool just the way it is. Lug looks Kent like. So probably Kent...which is cool.

Thank you, I just looked up kent lugs and that's definitely what they are since the lock washers match.  Is tung oil ok?  Whatever finish they used came off with the lugs so must have been gummy when screwed down.  Was thinking I'd acetone the outer shell to remove most of it and then spray lacquer or something that isn't like an oil or gum resin varnish, to prevent this issue in the future.

That's a lot of effort. You will learn about finishing that way. You should do it just for the experience, but you would be better off just buying a new shell. Your shell will be difficult to sand. The surface has undulations and looks like the plies separate in odd areas that will make it difficult to sand properly.