Any chance of getting an image of the marks in the encircled area?



It has what looks to be 3 unique JY tube stamps as well as the Express stamp from June 1929. I'd say with that it should approach $1500 U.S. of A. The locks are similar to what F.W. Keler offered. He was active at least by post WWI and more than likely up till WWII. I believe he was an actual maker and was sourced by the trade, of the likes of Heim & others.

Kind Regards,

Raimey
rse