I've seen him mentioned in a Russian language article under the name Чурапин (standard transliteration Churapin). "Ch" in his name is read as  "chess", "cheer"; "ou" transliteration to French to express the Russian letter/sound "у" (book).

There are a lot of results in Google for this last name, including WW2-era Soviet military on pamyat-naroda.ru.

Didn't he have ties with MI5 and provided information to them about the German counterfeit currency plan?  He had to be well placed to be in the know about this information.  Having a hard time reconciling his role in the counterfeiting intelligence with his stateless status and being an enlisted man or a junior office (not sure about his rank).  But then again, I don't know much about him.

Mike Vayser