Welcome to the forum mystery DBZ back poster.
A huge word of caution, of all the grading companies you could reach out to about some obscure thing, certainly for something pokemon related, CGC is literally the absolute last company I would ever trust their word on when it comes to anything ever. Indeed, I would consider their approval as being suspicious and contrary to whatever they are claiming. They enabled a scam that caused millions of dollars of chaotic damage, linked below.
If you are curious to prove, discover and provide evidence, this is the place for it! The forum is friendly. You have very knowledgeable people here. People who have stuck through pokemon cards through thick and thin, who know a lot, and whom are just interested in learning and discovery. I value the opinion of the sleuths here, some of whom may be able to help us learn more about your cards. Some people are surprisingly resourceful when it comes to contacts.
Personally, already you have piqued my interest, its a cool story. I don’t know if its true, I am always skeptical, but I am also always hopeful for something new and interesting to come to light.
If you want to help us see if these are legit, as I said, your phone applies some kind of weird smeary filter, so a good clean scan would help. A better camera close up would do, no top loader, no sleeve. We need to see the print dots. @Nightvulture is one of the kings of the print pattern as are others. I think that would be a great place for us to start. To just look at it the cards themselves and see if its possible. Story aside.
Thank you for having the bravery to post. Sorry I’m long winded. Welcome again.