Three Russian insulators as follows - actual postage additional:

CD 569.5 (tough style!) -- no markings -- flat base chip on back -- $25 (SOLD)

CD 568.7 no markings -- skirt ping / flake -- $15

CD 579.5 ПИВ. ОБщ (Livengoff partnership of glass works) -- just light flaking around the base (likely factory) -- scarce insulator - very heavy glass -- $90 (SOLD)