[Big Red Machine]

Hello,
Does anyone have any information on the 1981 MSA Discs? It appears that most discs classified as 1981 MSA Discs by PSA are misgraded and should have been slabbed as 1981 MSA Peter Pan / Sunbeam. The 1981 Promotional set from Michael Schechter & Associates (MSA) are the same size and design as 1981 MSA Mini Discs (Peter Pan / Sunbeam) but have MSA promotional branding on the back. I have been looking for a Johnny Bench. How difficult are these to find? Here is what the back of the discs looks like.