The early ones were "Made in Japan" marked. The Korean connection came later.
Don, any figures on the number of Grade II's produced??
You may run across a sidelock that's marked Miroku (but not Browning) that's essentially the same gun as the BSS Sidelock. I've seen two of those, and I have Miroku catalog copy indicating they were being made some 20 years before the BSS Sidelock appeared. Of course there were also Miroku boxlocks, but they show far more differences from the BSS than do the sidelocks. For one thing, most of the Miroku boxlocks we see in this country (most of which are marked Charles Daly) were DT/extractor guns.