I don't know if it's me, but I could have sworn there was another (ITV) prequel to OFAH, not just the recent 3 episodes of Rock & Chips. It featured a young actor who was dead ringer for a young David Jason, as well as all the ususal charachters, Trigger, Boysie, etc, in young 50s/60s mode. There's no mention of it on Wikipedia or other fan sites, though.