Oh, I think there were quite a few others (sorry, I got distracted onto other matters there). One that springs to mind is Mr & Mrs, which was originally a regional programme for TWW and subsequently HTV, then turned into a strange "Box and Cox" affair where series alternated between HTV and Border, then finally became a Border-only production. I don't think the HTV version was ever fully networked, but after Border took it over full-time it developed into a network programme. I can't remember the full details though.
(UK Game Shows says that Anglia also made a series in 1969, but I've no knowledge of that.)
Also STV's Now You See It, which according to UK Game Shows started as a regional programme in 1981 and migrated to the network in 1985.
Was Southern's Out of Town another one? Not sure.
It occasionally happened on the BBC as well. The BBC South children's series Hey Look That's Me! started in 1976 and moved to the network in 1980.