Oh god what's happening now?
I did admin officer for a course at 637 in 1991; it was originally formed at Gaydon in about '66 and move to Rissy in about 1974.
Rumour at the time I was there was it would be combined with 625 from South Cerney but then there was a policy change dictating that an SLMG school and a winch launched school could not operate from the same airfield simultaneously.
I've posted a bit about the fate of some of the Vigilants in 'Military Aviation'.