Thoughts on the 1954 Johnston Cookie Mathews?
 

Don’t look right to me. Looks like somebody tried really hard to make it look “old.”

https://ebay.us/m/8rKbwk

Rebacked?

Seller also doesn't put much effort into getting the item details right, so it could get rejected if it goes to authenticity guarantee.

Ha, I just saw that listing 10 minutes ago and had the same reaction.

The "stains" seller mentions look to me like some layering along the card edges - don't know what exactly would cause that, but seller has another '54 Johnston card for sale with similar layering. That one is Trainer Joe Taylor, and I have to think that faked cards would likely be players, not the team trainer. Seller has 100% positive rating on more than 6K reviews, so probably on the level, but you don't know where that card has been for the past 71 years, eh?