I was about to say the same thing. The only "evidence" for a 560 seems to be speculation on various forums that "there might have been one of them involved too because it fits the time period".
Somehow I doubt such a minor association is going to do much for the value even for the models where there *is* documentary evidence linking them to the thing you're thinking of. It's a bit like saying that every 1975 Ford Escort GL left in the world is now worth $690,000 because the one particular unit that once belonged to some other guy with hordes of devoted followers is "worth" that much. Only if you can lay your hands on one with verifiable fingerprints still on it will it be a different story.
I would say if you *do* actually want one get it quick before the last ones end up being burned for scrap in some dirty third-world metal recycling facility. Laptops that old are starting to get a little thin on the ground. It won't cost you much, the hard part will be finding a working unit.