In going through the September, 1971, issue of Playboy, looking for football phiotos in their annual college Pigskin Preview, I came across -- uh, maybe I should say, I found, an interesting article about collecting/investing. While baseball cards were mentioned -- exactly that, the two words "baseball cards" -- I found the lengthy article interesting and was struck by how accurate the advice remains nearly 30 years later.
https://docs.google.com/fileview?id=...MGM1ZmE4&hl=en