To be clear, a lot of it, as Gary said, is a kind of nostalgia. Also, the early ones with maple boards were made at a time when birdseye was easier to get, so they tend to have a lot more of it.Can you give me any information as to why the older ones are more desirable?
The early JOs do seem to have some kind of extra mojo about them, but I can't really define it. The Fralin J pickups capture that old-school J vibe better than the Lakland/Hansons, IMO. The latter has a little more of a modern vibe.
Overall, though, I think the US Laklands being made today are as good as they've ever made. My 2011 Glaub is incredible.