I can get a single JIS M5 x .90 die for $11, and then I could make all the M5 screws I wanted. Looks like a fellow could
get rich doing that Ha ha.
On further research, I see the engine screws are all M6, and that pitch did not change between old & new JIS. So, that's why the Rimfire kit will be ok. Although there are two M5s for the left cover.