I've never heard of one. People sometimes take Japanese releases, and swap in fake English insert/sticker/manual and try to pass it off as legit English release. This thwarts the whole "show me the pcbs" method of validation.
Since all languages are baked into the ROM, I just can't imagine they'd bother with any pcb differences. There's just no point.
The only way to know for sure would be to open a lot of carts, of course.