Here you go then. It was dark again, but I got some photos.
The locker looks like this, there are no exposed screws and the shrouds around the locks make it difficult to cut through the locks or shackles.
Here's another picture, only included because Boushti wandered into the shot.
Here is a shot of the contents, four road bikes and a (folded) trailer, still a bit of room left (but not enough for a full-size bike). They aren't difficult to load in like this. Note that it has a floor, there are fixing holes in this for bolting it down.
And another... It is tricky to get to the one at the back but I won't be using the TT bike until March-ish, at which point the 'cross bike will be placed at the back.