Help Identifying Overprint On Manchukuo Stamp

Struggling to identify this overprint. The stamp is Manchukuo, Scott #86, light green, 2 Fen. The overprint appears to be hand-stamped. Could this be for local use after the collapse of Manchukuo and the return of Northeast Provinces to China? Or possibly an overprint that Communist forces placed on Manchukuo stamps for use in the liberated areas of the Northeast? Can anyone read the overprint or provide any other help?

My own further searching online turned up the answer: Manchurian local overprint (machine, not hand-stamped), 1945-7, so indeed after the collapse of Manchukuo. The overprint reads "Chinese Post" on top, surcharge on left (50f on the 2f), "Temporary Use" on the right. Got all this from a great web site: http://www.manchukuostamps.com/MuTanKiang.htm

Thank you for posting results of your research.
That was my guess, but unsubstantiated.