Lot 5375-6:  7-inch Tractor Mount Mark V, proof firing, showing gun in full recoil. Secretary of the Navy Josephus Daniels Collection.     (6/5/2015).
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/127906254@N06">National Museum of the U.S. Navy</a>
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/127906254@N06/18317083590/">Lot 5375-6</a>