This situation is reminiscent of the rash of "re-backed" T206's that occurred 22 years ago.
Circa 1999 - 2000, a bunch of T206's were in circulation that were being sold on Ebay (and at Shows) that were FAKES.
These T206's were very professionally altered, and these cards (initially) fooled many collectors, and even the Grading Co's.
Fortunately, there were some of us T206 collectors who instantly recognized that these T206 cards were fakes because their
front / back combos were
impossible
Here is a list of some the examples of these FAKES.....
Matty (portrait) with a
red HINDU back (PSA and SGC graded)
Matty (portrait) with a
SOVEREIGN 460 back (PSA graded)
Green
Cobb with a
red HINDU back
Green
Cobb with a
CYCLE 350 back
Johnson (pitching) with
BROAD LEAF 350 back
Johnson (portrait) with
BROAD LEAF 350 back
TED Z
T206 Reference
.