My recollection is of Channel 4 coming to Reigate around the end of January 1985. We were never supposed to get Channel 5 at all on analogue but they squeezed that one in in 2003.
Yes, very odd for C5 to be investing in new analogue transmitters, 5 years after digital platforms had launched.
They added Reigate, Hastings, Brighton, and Tunbridge Wells. Guildford was on the list too, but never happened because they couldn't get clearance for using UHF Ch 36 (still being used for radar at a couple of airfields, though the big one at Heathrow had ceased in the 90s I think)