I think it's the same head as YM2000 (which was also sold in USA with name YM240). But verify this before spending any money! There could be early/late versions, for example. YM2000 was very popular, so today there may be more of them in scrap yards.
And I think we've read here that a YM2000 engine (complete) is a bolt-in replacement into YM2210. The rated horsepower is 10% less, but the engines are nearly identical so this difference should not be significant in actual use.
These are just ideas to start research!