I so know how you feel, I really do! I'm feeling it vicariously through you right now in fact, lol. That's so cool, yes. I think you just stumbled across a really nice score. By my estimation you're due for an exciting find to cheer you up anyway.
They're not just some run of the mill boring good deal either. They're unique and not common in North America, but still JBL, a recognized and respected name. You know I'll bet if you put those on Audiogon you could get 5 - 600 bucks for them. Maybe even more in parts, but it sounds like they're keepers to me.
Can you access the internal drivers at all? Like through the top maybe? I'm just curious. I'd be bumping some bassy tunes and hold my hand around the edges of the "port" to see if I could feel some air moving. Then I'd shine a flashlight through the top glass and port and watch the drivers on the inside move. In fact I'd prolly take 'em apart just to get a good look inside, but that's me. I've always been like that