[James A Pratt III]

Some armor comments BCRS Vol 6 page 151 "..tanks with red stars on their turrets."

The Eastern Front Armor Camouflage and markings 1941 to 1945 SJ Zaloga & J Grandsen
on the Red star on Soviet tanks: "It was applied occasionally by crews on an unofficial basis during the course of the war, and it's use increased dramatically in the final year of the war. However, even then it was far from commonplace."

There were Guards Tanks units that did have the Guards badge which includes a red star painted on them.

Also during one 1943 offensive there was an air identity marking in the form of a white triangle with a red star on it painted on the tops of turrets.

i hope this is of some use.