SkyCop, you could try 123.1 as listed in back of RAF "yellow book" instead of Unicom. (Incidentally, the old Unicom freq is still currently listed in that publication!)
Marco, the standard AIC on emegencies in UK, (can't remember the number), used to list Unicom until about 18 months ago. Then the reference to it was simply removed without telling anyone!
This state of affairs will blunder on until Max Headworthy gets a grip or 2 police choppers collide.