They may be Russian. However, you would probably have scan through lots of Cinderella listings on eBay
to find similar or an exact match for these. To my eyes, they look very similar to eBay
items I have seen offered by seller, or sellers in Russia.
If you searched for "Cinderella stamps" only by Russian sellers, this would save a lot of time.
Oops! Just "ran into" this seller on eBay
. Seller is "1_07553" and calls him/herself copystamps. His/her store shows that 2 sets of these are available.