1987 Sportflics - Superstar Discs Baseball Forum

Two questions about this set:

1. From what I've read, these were only available through mail-in offer from 1987 Sportflics when sending in an offer card and $5. Shouldn't this set be a "Mail-In" on that main 1987 one, similar to the mail-in offers Topps did during that time?

2. There are four different offer cards for Series 1 through 4 (discs #1-16). How did collectors get #17 Pete Rose or #18 Eric Davis?