LM, The MOD hired Concorde from BAC (IIRC) for a supersonic intercept practice. It flew a circuit around the North Sea at M 2.0 as a target for each fighter wing in turn. It may even have been late 60s as I recall the Notam and exercise instruction but from 1970 I was overseas.
This was also the time of 'big' exercises like Lime Jug, the first Highwood, Bersatu Pardu. We had a budget for proper training.