I'm about to submitt some Japanese uniforms: I made summer and winter Admiral uniforms. It took a while since I also created a face for them and some decorations, like the Order of the Chrysantemum.
References are always difficult to find. If we had digitilized images of the official designs by the old governments, that would be AWESOME, but unfortunately, we have to rely uniquely on Google or even screenshots. I felt this when, excited about the Japanese project, I tried to look after the "Tenno gofuku" the uniform Hirohito used to wear during the war, and found only one photo of questionable quality.