2004 (UK Only)
After Rex's steampipe began leaking one day and Frank had to take his train, the Small Controller started thinking and so he arranged for Jock to be built. When Jock first came out for testing he was still unnamed. Douglas, remembering his days on the Highland Railway in his youth, suggested the name "Jock" for the new engine, and the name stuck.
- 2004 (UK Only)
- Jock was the last character to be made by ERTL before Take-Along took over.