According to an article by Wade Sampson on mouseplanet.com, Walt Disney later attempted a Gray Seal TV show.
Episode titles:
1. The Grey Seal
2. The Stolen Rubies
3. The Counterfeit Five
4. The Metzer Murder Mystery
5. A Fight for Honor
6. Below the Deadline
7. The Devil's Work
8. The Underdog
9. The Alibi
10. Two Crooks and a Knave
11. A Rogue's Defeat
12. The Man Higher Up
13. Good for Evil
14. A Sheep Among Wolves
15. The Tapped Wires
16. The Victory