Interior lighting???

[lym]

That's V21, the box on Verdun Road.

https://tardisbuilders.com/index.php?topic=8310

It was indeed one of the early wooden/concrete boxes. Not sure if the roof was unpainted or not - I've also heard that the paint on these early ones was fairly prone to running. Interestingly it's also been noted that this one in particular has windows that are longer than the panels, something that hasn't been seen on any other Mark 1 yet.

[Andrew Harvey]

Thanks for that re-direction there Lym! I had no idea those beautiful pictures were there! I clearly see now the windows being longer than the other panels. Cor! Great stuff.
  Andrew

[dr hue]

Avoncroft Museum - City of London - 1953 Pattern PA3 Police pillar
I believe this is Post 33? Its hard to tell after the Database was corrupted after the forum shutdown a few years ago.

33 here:

https://tardisbuilders.com/index.php?topic=6694.msg88901#msg88901