M210909a
Crowned oval with letters "COR" above "W. GERMANY".
It seems that this COR was a distributor or retailer dealing with items from various countries, including Germany, Japan and Taiwan.
M210909a
Crowned oval with letters "COR" above "W. GERMANY".
M210909b
Crowned oval with letters "COR", date, series name, and "MADE IN JAPAN" sticker.
M210909c
Crowned oval with letters "COR", date, series name, and "TAIWAN" sticker.
M210909d
Crowned oval with letters "COR" above "TAIWAN".
M210909e
Crowned oval with letters "COR" (here above the date "1987").