Boy that looks familiar. I also have a 73 overlander and your's is pretty much an exact match except of course for condition. That roll up awning over the front window is interesting, never seen that before, but on mine, its on the rear window, so no reason they couldn't have mounted one on the front.
Concur with it being a "Field find". All bets are off on condition. Not sure what is meant by "rusting out in a few places". It does have some damage and is missing some parts, but in the grand scheme of things, they are replaceable.
Value? Keeping in mind that it's a Florida trailer (not good, too humid) I'd say 1-2 grand at best. Most of that value would be in the parts; sheet-metal, windows, the awnings. Even without a shell off, it would be a huge job to get it road worthy again. I paid 6500 for mine in much better shape 2.5 years ago and have dumped probably 5 grand in it just in materials, not counting labor and no shell off. And you may have a bit of a time getting it out of the woods, it looks like the wheels are off on one side.
Good luck, dont be afraid to pass it by. Sometimes its better to spend the money up front than to take on a basket case.