Legit USSR Surcharge Overprint Or Illegally Made For Collectors?

I received these 2 blocks from kiloware purchase and cannot decide if these overprints were added on illegally (like some similiar Ukraine overprints from early nineties I have seen) or legit printed for use.
I would appreciate any knowledge shared on these. I'm having fun sorting through this pound of stamps, but it's making me realize I have so much to learn!
Thank you for reading this, happy collecting to all!

Those are fake overprints on the stamps ,overprinted in a Baltic country .

I have so many different private (non-postal) overprints on that particular set of Soviet definitives, and most of them overprinted Ukraine (because - besides the three Baltics, Ukraine was the first to declare independence from the USSR), but some overprints like these do not denote a nationality.

They have no postal value, and are merely fantasies. Some were actually overprinted in New York City, after the Soviet stocks were replaced with Russia stamps. But they are still interesting nonetheless. The pattern printed over the 10/20 ruble and 200/300 ruble stamps is intricate and very interesting…

You can certainly collect these if you like; since I have a specialized collection of Ukraine, I am planning to mount mine in the pages in between the 1918-20s issues and the modern Ukraine stamps. (I have a separate album for the Independent Ukraine issues from the 1940s-80s, these are all Cinderellas and have no postal value but again, are still quite collectible).

All the best! If someone has created a catalogue for these fake issues, I'll let you know. Cheers!

I'm sorry for late reply.... just now checked back!
Thank you for the info. Even if cinderella, I also find the overprint interesting looking and happy to have in my collection.