Jeff, the friend of mine had hammer Sauer 20g and his uncle bought this Sauer in 1912 (don't remember exactly now) from factory and through the dealer. I remember I asked this question here when Sauer made according s/n and people say following your article gun made 2 years later, than this gun been sold.
Sorry, I didn't read your article, but let me ask one question, do you have any official Sauer' data or records or this list of dates is just your thoughts and calculations?

Geno.