The copy of the Daily Mirror that Snowy holds (with the headline "A Very Wide Gulf Remains") is from 14th October 1968 suggesting that this episode was produced around a year before it was broadcast.
Body count: 3.
Gloria Marsh's song, "Out To Get You", was written by Chris Andrews. It also featured in ITC's Portrait of Brenda (1969), and was actually released on the Major Minor label (MM 553) in 1968, performed by Sandra Bryant.
As revealed in exterior shots (which show it's actually playing "Beauty & the Beast"), the Palace Theatre is in Watford. Opened in 1908, it continues to be a live performance venue as of 2023.