Who was the counterfeiter of US $100 bills in Germany around 1929?

Big thanks to Bob Ayers for his excellent article, "$100 Counterfeit Federal Reserve Notes" (SPMC Sept/Oct 2019, #323). '

Some of the $100 bills, produced for the Soviet Union near Berlin, were laundered through the Berlin bank, Sass & Martini, in late 1929, which had been recently purchased by Communist sympathizers in Germany, and which was shuttered by the Berlin police in early 1930. 

Along with a cousin of mine, I've been trying to dig deeper, as the bank was sold to the new owners by our grandfather. We've got some documents relating to the bank sale, but there's more digging to do and I'd welcome any info others may have about this. 

One specific question: Who was the counterfeiter who designed and produced the bills? Bob Ayers mentions, "The Soviet OGPU office (Fourth Department Clandestine Documents bureau) in Moscow was tasked with engraving the plates and printing the counterfeits. This Moscow-centric effort was supported in part by a German engraver in the German Communist Party." Do we know who that engraver was? 

I recently found a possible candidate, Ivan Grigorjevich Miasojedov (see https://zdes.spbu.ru/images/working_papers/wp_2018/WP_8_Kotelnikov.pdf ). Miasojedov was a respected artist from Kiev, not sympathetic to the Bolsheviks, but he had a history of counterfeiting, including US $100 bills! He was arrested and jailed twice for counterfeiting, first around 1923, and then around 1932. The second trial (there's a photo of him at trial in the above article, quite a character!) may have been for this particular counterfeiting on behalf of the Soviets, despite his earlier anti-Bolshevik sentiments. It's hard for me to imagine multiple artists around Berlin in the 1920s all producing fake hundred dollar bill engravings, so I suspect Miasojedov. 

Any further info that may shed more light? 

-David Schoenbach