If I recall in his SCD article on the 63 cropping differences George Vrechek did note the difference on the back of the McBean card. I think the article had comparison scans of the differences in all the cards involved ( 11 ? ), which was very helpful in tracking them down.
Not sure if it showed up earlier in this thread
edit---here is SCD article
http://r.search.yahoo.com/_ylt=A0geJ...zWC9manHnPNYw-