The pics are a bit confusing as there are both ST80 & ST100 pics in the same folder. How do you know the new one is an ST100?
Tokai apparently forgot to stamp some pickups - perhaps they ran out of ink sometimes? They certainly never imagined we'd be discussing it 30 years later! The pickups in my 1984 Goldstar ST50 are unstamped, though I'm pretty sure they're Us. Apart from this feature, everything else is original, including the MADE IN JAPAN & 50 stickers on the back of the neck.
I wouldn't lose any sleep over the missing stamp, if I was you.