Well..... Why do you think it is Nippon? With no markings at all it is
probably a product for the domestic market . Sorry I cannot be more
help. There are a couple of Nippon experts on this board and hopefully
one of them will jump in.
Google Normally China. This mark was used post WWII and is later than
Occupied Japan (as the mark does not say occupied Japan). Somewhere in
the late 50's or 60's I would guess. This mark gave me my laugh for the
day. I wonder what is when it is not ...