I was just entering some of these and noticed the CL generic entries and did not find any other than the specific cards. I did notice some that are printed on a different/much darker card stock (same as wax box material) and wondering if anyone with a good selection of these would be interested in working on putting a list together of the darker/heavier cardstock variations? There are a few images on TCDB of darker ones already. I would guess all came in both variations. Probably a change made to prevent a bright light from revealing the hidden text without scratching off the silver.
I have
Ernie Banks
Cecil Fielder
Tom Seaver
Maury Wills
With the darker/heavier cardstock
Of the images showing the darker backs only one looks to be credible with the front and back images submitted by the same person.
Roger Clemens
In addition I have verified.
Jose Canseco
Willie Hernandez
Stan Musial
Nolan Ryan