1977-78 O-Pee-Chee & Topps

This set had glossy insert photos with either rounded or square corners. All this time, I thought that the rounded corner versions were the American cards, and the square corners were Canadian. This is because the square ones I have are stamped on the back with O-Pee-Chee, and the rounded corners say Topps. But I recently learned there are actually both American and Canadian variations of both formats – meaning a total of 16 different inserts featuring Bruins players. I'm going to stick with my 8 and be happy.

Dave Forbes, #143, got traded to the Capitals during the season. This was noted on his O-Pee-Chee card with a changed logo and a "Now with Washington" stamp, but the Topps version is oblivious. I have a blank back error card of the O-Pee-Chee variation (which you could tell from the paper stock, even if the fronts were the same).