Greenbank and Mystery solved!

Very warm again today. A visit to Greenbank.
Also finally solved the Mystery box! ... thanks to IainatCreel who gave me the lead to get in touch with StuartDb the transport guru. Stuart had said he knew it was to do with the Corporation's trams. Another friend who lives near the area sent me a photo of the other side ( I couldn't take one that day as I was in a hurry and the road was very busy). This confirmed that it was indeed the Corporation's trams with the logo GCT, Glasgow Corporation Trams, on the box. So it was an electricity junction box for the trams with a phone box on top for the inspectors to use. Mystery solved. All this in the extras. Thanks again to Iain, Stuart and everyone else who took an interest or contributed in getting this mystery solved.