Planko: It is merely my 'surmisation' but .. I believe they may have built the little tail-skid trolley to prevent unintentional contact with the ground while manoeuvring her. I think that even with the oleos fully pumped the 'stinger' may sit precariously close to the ground and its my guess that they are simply being ultra-cautious. As you know, even a small incline in the surface can bring the tail fairly low and, if they were pushing her backwards, it could inflict some unwanted damage on the now delicate beast.
Yoyo: Thank you for your investigative work! Hopefully you've come up with the location, great stuff!
Planemike: The CAA have however allocated some pretty rude registrations and I believe it was PPRuNer Brilliant Stuff who alluded some pages back to one craft in particular and which I think I promised to do a piece on - I shall have to get round to it. The 'rude' craft in question has been mentioned on PPRuNe (long ago) although not on the Nostalgia Thread.
By the way, did you notice the tail section of your beloved De Havilland Express in Yoyo's photograph?