Look too good to be of the era. I imagine many will shy away...
Had these not been genuine or "of the era," PSA would not have taken the time to grade and slab them. They would have been rejected outright. From the article, these were stored away in a closed box, and not exposed to light or moisture, from someone who was a collector-type person, to begin with.
The Honus Wagner card (from this find) is already up to $55,000.00 at Heritage.
This is no different that when an early stone litho poster is found, which may have sat folded in a drawer, file or box, and is in almost mint condition 70-80 years later.
The only ones that will shy away are the ones whose pockets aren't quite deep enough.