Posted By:
Eric BrehmIf that card grades EX-MT or better, it is worth $5000 or more. Thus it is worth the cost of submission to a grading service, to get an opinion as to whether or not it is authentic and un-altered. If your grandfather owned it for a long period of time, it is likely not trimmed. But if it is trimmed, the grading service will likely detect this and, either way, you will have a professional opinion of what you've got.
The nominal size for 1933 Goudey Baseball cards is 2 3/8 by 2 7/8 inches. However they do vary in size -- by my estimation as much as 1/32 of an inch in either or both dimensions, smaller or larger. Thus if the card is that much smaller in either dimension, you might suspect trimming, but I don't think it would be conclusive. The best evaluation can probably be obtained by having a professional inspect the actual edges of the card for evidence of alteration.