Keep in mind there were three series of YM2000. The differences are mostly sheet metal and the instrument panel, with a few instances where the right series has to be known to get the right parts.
1) Headlights external on the sides of the grille, and the hood hinges at the back like a car. Painted green. (75~77??)
2) The common one. (77~79?)
3) Common, plus plastic instrument panel and more hood side panels. (YM2000B) (79???)
And the US version (YM240) was like #1 and 2, plus it added an external air cleaner in the final year. (1981). All years green.