Geno,

I think you were correct in your 1st post. The PS is the mark of Prosper Schlemmer who was located at Walter Jamar, 189 a Ans, 1924-1927. He held at least one patent. He seems to have died or left the business. However Yvette Schlemmer was active 1927-1934. Yvette was either his son or brother. In any case, it would not be uncommon from him to take over the old trade mark and change it a bit.

http://damascus-barrels.com/Belgian_Trade_Marks.html

Pete

http://www.damascus-barrels.com/Movie.html