This one is a CC 638 unembossed, in light green glass. Probably late 1960s to 1970s vintage, while the Ukraine was still a part the Soviet Union. The mold line does not go across the top of the insulator. Normal embossing for these is "WC 10 D" (Cyrillic letters for SS 10 D" This is most likely a Lviv Insulator Plant product, see the following URLs:

They also explain the apparent lack of insulators date marked for the 1980s and 1990s, due to economic problems over there.

http://www.energyglass.com.ua/en/?topic=ns18a

and

http://www.electra-trade.com/en/pin-insulators.html

[IFONA CD 638]