I've smoked a bunch of real old cigars, and still have a handful or so. If you don't know the person they arebcoming from or how they were cared for and you can't inspect them, I'd strongly suggest you steer clear.
I've smoked from the same batch of Betsy Ross that Tim mentioned.
Here's a link to the review. It was a decent smoke. Some others that werent quite so old were much better. The only reason I mention it is that real old doesn't mean real good.