What 51studebaker is showing you is the catalog listings from Scott Specialized (or at least those are Scott numbers). Scott 153 was not issued with the specimen overprint as shown above. Perhaps I'm having catalog blindness but I don't even see that design listed in the specimen section. Possible fake?
Never know why. I'm not 100% certain it's fake, I'm just saying I don't see a listing in Scott specialized for that stamp. The Scott system simply uses an "S" in front of the catalog number for "specimen". So there would be either a S142, S153, S164, S175 or S200 (last 2 were the special printings) since those are all the ˘24 designs for that stamp. There are no Scott numbers for any of those in the specimen stamp section (2017 edition).