The original fuel pump was still on the engine block when I removed it from the chassis. It doubles up as a fuel pump and a vacuum pump and is driven off of the cam shaft.
After sitting for many years, the pump inside was in a pretty sorry state. Corrosion had built up inside and seized all of the valves. Even the diaphragms crumbled to bits when handled to remove them.
After a session in the blast cabinet, the body and caps came up nicely. I initially ordered an original rebuild kit for the fuel pump which I was only able to use half of as the diaphragms included were not suitable for modern fuel. I then found another kit from LWD Parts which made from modern materials and allowed me to complete the rebuild.