Before the cab and chassis assemblies can be fixed together the instrument binnacle, radio and wiring, seats, and roof tarp were brush painted with Vallejo acrylics and the instrument decals added. My kit included two sets of decals which was fortunate as decal number one did not represent the dial in anyway shape or form. Decal number two was used twice to represent the largest dials and some extra placards were also added from my decal spares box.
To prepare for the external decals I used VMS satin varnish. This can be airbrushed direct from the bottle with a little thinner giving a good wet coat to level. It can be left a couple of hours inbetween coats if required.
Below is the only internal cab reference image I have. The instrument binnacle appears to sit a little higher than it does in the open top wooden cargo variant. As already mentioned I am not 100% sure that a radio was ever fitted to these vehicles.