Ian,
Well you can rule out an F/G31-32. The front brake drum is on the LH side, so it has to be one of the side-valve models. (You have to Photoshop the image to get the brake drum visible.) Just enough of the top of the timing chest is visible looking through the engine bay (it is white colored) to identify as a big twin. Not a 1933, as the dynamo over the front cylinder would have blocked the view. I think it is an E/H31-32 model, as it looks like it has the old pattern forks. There is a suggestion of the extension springs behind the girder and bit of bright work for the upper perch nut. The D would have the central compression spring. But I have to admit it is a bit like reading tea leaves.
A big twin certainly make sense as a chair is fitted, but they did make sidecars for the lightweights too. The shape of the sidecar body is appropriate for a Douglas Sports. The Touring had a different nose. The only thing that looks wrong is the cut of the door seems a bit square. The catalog literature I have seen shows the door (when fitted) with a big swooping curve to the bottom edge. However the shape of the doors could have changed over the years.
The registration is CG2775 or CC2775.
-Doug
