You are right, Steph, a good photo ( I believe it to be the complete image) with the sharpest point of the lens being to the right of the frame. At this distance in time we'll not know why.
And thank you Dave for your observations. My image processing software is stone age but I'm familiar with it so will continue to use it. There is a "Noise" filter but not a "Denoise". However I believe the "Despeckle" instruction does the same thing. I've applied it to the two images (both sharpened) below, so see what you think. Both have been cleaned up to a reasonable extent but I've not spent the many hours which would be required to do a perfect job.
I've not tried to build up the individual vehicle numbers within the set which is the subject of the last photo but I agree that it may be possible from the single vehicle number which is readable. The vehicle next to it may be readable, but there's an element of guesswork involved.
The first is, I believe, an Oerlikon unit, once again at Kensington Olympia. In fact that is, if I'm not mistaken, the Olympia exhibition venue in the background. There also appears to be a train in what I would recognise as the London Transport/TfL bay, although I can't determine the likely stock type. Unfortunately lots of camera movement.
The one below, also Kensington Olympia, is a bit of an oddity, though. The vehicle on the right appears to have similarities to an Oerlikon trailer, but it's coupled to a vehicle which is clearly not of the same type and there appears to be a corridor connection. My knowledge of things LNWR is insufficient to even make a guess.
Brian