The story seems as questionable as anything the other guy have pointed out.
The points that stick out to me are;
1. The guy somehow googled you and went to the trouble to find and send you pictures. Not anybody else that may have responded to the thread.
2. Nobody here has come forth and said they've seen this type of disk before. Including the one person on the planet with more of this stuff than anybody.
3. The font is debatable for being era correct but the white being as white as it is sure is suspect.

My guess, someone figured out you have money to throw at your toys and would be willing to pay huge for them. That he said they weren't for sale doesn't mean anything, probably just priming the pump to get you to pay whatever he thinks he can get you for.