Having got the right parts, Bob and Mike set about reassembling the compressor and fitting it back into 258. Below is a photo of all the parts on the table prior to being put back into the vehicle. The pink gasket near the camera was the gasket we had trouble sourcing.
Below is a photo of the area of the engine that the compressor was put back in. As you can see there really not much space to get to it. At part during the refitting Bob was inside and Mike was behind the vehicle trying to get the best access to it.
And a photo of half of the compressor attached back into the engine.