These cases could easily be detected by atypically styled upper kanji 勲 - Merit.
Comparison with a "typical" inscription for an "early" (1888-late 1930s) cases (on the example of 6th class cases).
Comparison with a "typical" inscription for a "late" (late 1930s- 2003) cases...
3rd class sacredtreasure awarded in 1956
caseforsacredtreasureorder
inscription styles of sacredtreasureorder
japanese awards and decorations
japanese medal
japanese order
japanese order of sacredtreasuresacredtreasureorder
勲三等瑞宝章
勲六等瑞宝章
瑞宝章