Posted By:
WilliamI would be more concerned if the card is trimmed/altered or grossly overgraded as being concerned if it is a real card.
Older CSA graded cards (graded in the mid-to late 1990's) in holders that look similar to PSA slabs have a better chance of being ok. I have cracked out an crossed several cards (1967 Mantle CSA 8, etc) to PSA in the same grade.
If the card is in a newer CSA holder (I am not sure how to describe them), there is a better chance than not the card is alter/trimmed.