I dont Live in South West England but looking at the Transmitters in Service caption I would say between the Spring of 1974 and the Winter of 1975. . The Plympton Relay Near Plymouth came on the air 23rg November 1973 Followed by the Isles Of Scilly Relay which came on the air 3rd May 1974. The Next Relay Transmitter in the area to come on the air was Exeter St Thomas which Started Broadcasting on the 28th November 1975 which is not in the Transmitters in Service List above.
STV startup is called Scotlandia, I fondly remember it as a child!! Galloping around the sitting room and bouncing up and down on the settee much to the annoyance of my mum and dad!!!🤣🤣🤣
I dont Live in the South Wales or West Of England Area but I Seem to remember here in Granada Land the ITA Piccasso Tuning Caption shown in the Video was shown using the Transmitter Name , In Granada's Case Winter Hill or Emley Moor depending on What side of the Pennines you lived. and I'm sure this was the Same in every other ITA Region in the Country . However as the demand for the expansion for ITV Grew , The ITA decided around 1965 to replace the Transmitter Name with with the Region the Transmitter Served as new relay transmitters were brought into service. Therefore Winter Hill/Emley Moor was replaced with North and St Hilary was replaced with South Wales and West on the Piccasso Tuning Captions. This Continued till 31st July 1968 after the New Programme contract companies commenced Broadcasting, When the ITA decided to replace the Region Names with the Programme Company Name .
ITV2, but didn't have Carlton Two, Granada Two, YTV2, LWT2, Central Two, HTV2, UTV2, Anglia Two, Meridian Two, Westcountry Two, Tyne Tees Two, STV2, Grampian Two, CTV2 and Border Two.
And being 1972 another Sunday of absolute crap starting with adult education, religion, politics, some rubbish afternoon film, more religion and nothing will really get going until 7.15 tonight!