Although I don't know the true origin of this particular weapon, Lenin and Trotsky also gave away huge quantities of obsolete and then-current small arms to the Communists in China during the years immediately after WW1--trainloads of em, in fact, into northern China and Manchuria, thru Siberia.
There is every possibility that this rifle wasn't a R-JW capture, but is a weapon captured by Japanese forces from the Chinese during the Manchuria invasion and occupation in the 1930s.
Just a thought. Prob'ly will never know the answer.