Back in the dim and distant my dad had a towing hitch welded to the chassis. Many years later most of it was sawn off. Time to remove the remainder. Straightforward, just take care not to cut into the chassis with the angle grinder. Two cutting discs later and the job was done.
The bulkhead is in a poor state and could do with being replaced. A piece below the throttle pedal just fell away when I was taking the bulkhead out.
This photo shows the bit that fell off separated into its three layers. As it stands it is comprised of a thick sandwich of 1/4" 3-ply between sheets of 0.015" galvanised steel. Small, bent over nails hold the edges and corners of the sandwich together. Close inspection suggests that the nails are driven through the metal and wood then sheared off with a cold chisel.
So, what do I replace it with? My first thought was a nice piece of aluminium plate which has been used in this application by others, but I finally decided to replace like for like.