More info I just discovered on Wikipedia (
http://en.wikipedia.org/wiki/Manchukuo). The rising sun doesn't seem to be the Manchu-kuo flag, though I thought I had determined that when I was investigating these swords several years ago. Based on the Wikipedia entry, what I described as a flower pattern on the scabbard was, I think, the Imperial crest.
I have to back track and see where I got the idea that the second flag was Manchuria.