A couple of weeks ago I too saw a Scout - in formation with an Allouette 2 and Sioux (Bell 47) over Oxfordshire. AAC type at work (who has hours on all 3) informed me that it was the Army Historic Flt (sorry if that is not its proper title!).
I saw a Wasp parked outside Tescos at Brooklands about 3 years ago. How bizarre. I think it was part of an exhibition to raise money, or recruits, or both.