The CO's dvr at Harrogate used to wear one as did a Tfc Offr, who later went on to become my Sqn Cdr, and incidentally probably the best one, at 252 in JHQ. I seem to remember the bandies used to wear them on occasion too.
smoojalooge - I will see if I can dig out a pic of a SNCO in the Middlesex Yeomanry wearing one. Being a unit who always 'do their own thing and f*** the rest of the army' I can remember c*nt caps being worn within the last couple of years, by the rebelious few. Also acknowledge it is an HQ thing.