Bob's ongoing catalogue of railroad handstamp cancels on documentary battleships has just been updated, with many new examples of cancels.
I encourage you to visit his site, Battleship Revenues.
The site has been the primary home for the volume "Battleship Desk Reference", which is essential for proprietary handstamp cancel collectors on the battleships. Bob's recent efforts have been focused on railroad documentary cancels.
Examples of cancels posted to the site Battleship Revenues.