There are 1 Knueppel/Flagg trading cards tracked on HobbyCardIndex, spanning Basketball. The most valuable is the Knueppel/Flagg #DPR-KK at $263.19 raw.
Source: HobbyCardIndex · Updated daily · https://hobbycardindex.com/players/knueppel-flaggKnueppel/Flagg Cards
1 cards · Basketball