Inklinks is intrigued as to the use of this Waterman letterpress block stamp. A wooden block with a metal stamp nailed on it, it has been well used judging from the ink stains on the wood. It comes from a time when companies did not mind apostrophes and took pains to include them in their logos. Waterman dropped the apostrophe probably around the 1950s (ink history experts may know more) so I am guessing that this is a pre-1950s piece. Note the Art Deco styled border of the stamp.
Great piece of ink history on sale at Inklinks.