Walther Flare Pistol Pics

[Ida-Alp]

I'm interested in an explaination of the markings on the left side, especially the mark under the screw. This pistol is stainless and weighs about 5 lbs. I think it's Navy. I found a drawing of it in Gene Gangarosa's
Walther book along with a brief history. They were made in both single and double barrel models, and later in the war were made of cheaper and lighter metal. I'd also like to know if anyone has one in his collection. Thanks for the help--Al