Perhaps this;
It almost resembled a Garden shed with a very short yet High fixed tail rotor, (angular illusion!), and a small diameter main rotor I think it had three blades , was powered by what sounded to be a four cylider piston and was getting along nicely at about 50 /60 knots.
It was darkish green or blue and looked in good nick flying at about 350/450 ft, looked very ancient."
Filming starts soon for the forthcoming Captain Scarlet film. 
WG-13;
"Confined area? You could get a Sqn of Lynx in there!"
The last Lynx Squadron I was in was very short of Lynx ! Despite this,we also had to share them with the other Squadron!
Mighty Gem;
It was that time of year!