Dang, too bad. There is just *nothing* inside there to put a screw into. The thin lid and countersinking didn't worry
me as much. But yes, with that frame all open like that, I don't think there's anywhere to put a screw in.
As I recall, when I did this, it was one of the Kato engines with the metal truck frame and plastic snap-over
cover, so I could drill into metal and there was plenty of it inside there to hold a screw.