One of the cards I got in my trade with Night Owl was the 1983 Fleer 408, Ed Glynn, which is listed in Beckett as an error card because it had a picture of Bud Anderson on the front.
At first it seemed pretty straightforward to me. Fleer confused two Long Islanders with blonde mustaches. On the front was Bud Anderson, who pitched at Clarke High School in Westbury, and on the back is the clearly thinner mustache on Ed Glynn, who pitched at Francis Lewis High School in Flushing. (Hey, Queens is a part of Long Island.)
But look closer on the front of the card. Bud Anderson is not alone in the picture - standing behind him is #48. Who wore #48 on the Indians? Ed Glynn! So he is on the card after all! It's not an error at all - Fleer just chose a picture where Glynn was out of focus and his head was cropped off, and his teammate was in the foreground in focus. But remember, in the early 1980s Fleer's photo selection was not that stellar anyway.
Speaking of Long Island pitching stars, I also got this card of former Bethpage High School standout Joe Sambito gracing a young Dodger fan with his presence. The kid is so excited to meet a major league player that he can barely contain his yawn.