Another few hours in the garage and I did two things.  I measured the car from front to back and side to side and decided that the bulkhead is straight after all.  I think it needs to be encouraged to move over a little and the shroud itself is a little wayward but I hope I can get there with old fashioned methods of persuasion.

I then turned to the petrol gauge (I know there is a lack of logical progression going on here but hey ho).  When I bought the car the previous owner said that the gauge was missing so I was very surprised to find it in one of the boxes when I was rummaging about one day, even if it is a little tired.

As you can see the glass is broken and the gauge itself is a tad grimy.

With the glass removed all I need to do was clean away the insects and get the blue plastic strip back into place around the edge of the fascia.

However, I couldn't get the blue strip out so decided to take it completely apart.  I realised that this was a mistake fairly quickly.  I'm a blithering idiot sometimes.  I turned two small nuts on the rear of the casing which span the coils round on the inside and snapped the wires.  Damn.  So I'm now on the hunt for the type of person who can re-wire 60 year old petrol gauges.  If you know anybody suitable would you mind putting them in touch with me please.