Here's my two seater version, bought by one of our members and now in New Zealand.

There is a 'covered' seat in the casting which I machined out. The baseplate was irretrievably rusty, gone to holes in places so I made a mould from another baseplate in good condition and cast a resin one. AS it's not feasible to make very thin resin casts I made it much thicker and cross-drilled it for new axles. To get the driver and navigator in needed recesses as shown. To make the new thick base fit I had to machine into the edges of the car casting... 

Folding the navigators arms proved a challenge too.