Saw on another site that for the TOPPS Vintage Star Wars cards, there are actually 2 versions of all base cards

"The cards have either one star or two stars on the front before the copyright info at the bottom , it indicated the sheet the card came from in the print run . there exists full sets of cards and stickers for each series , blue ,red,yellow,green and orange in both star types"

Looks like I will be spending the weekend going through my sets, and then figuring out the best way to find and collect the one or two star cards I need, and also figuring out how I am going to store all the additional cards

At least this will give me something more to look for at the next Philly Show

I allways thought those stars indicated a picture puzzle piece or a text card.

They exist for Star Trek too. They seem to relate to the printing sheet. Someone I know of has actively tried to complete the Trek set but hasn't yet found them all.
I have some handwritten notes from the production of the Topps 76 set and it shows how the cards were to be laid out on the sheet. It's penciled in that sheet A is * and sheet B is **.
I have not yet persued this for my own collection, though it's tempting with this down time in trek releases.