A month and a half back, there was a very significant auction of American pocket watches held by Bonhams in New York. All of them came from a single collection, and many pieces resurfaced that last sold at the Atwood Time Museum auction in 2000.
I was not able to attend the sale or even to bid on any of the lots, but several good friends of mine bought significant pieces from the auction(which, incidentally, went very inexpensively as a whole) and I've had a good chance to view many of the sold items "in hand" since then.
This is a sale that will go down in history. Even though I was not part of the auction, I was fortunate to be able to acquire one of sale catalogs. The catalog is really a well-done publication, and goes down in the historical record as providing at least some provenance for all the pieces sold in the auction.