You can't really chop or modify it, because it's a completely different design.
Trade is the only option.
Do you have the adapter plate for the supply unit? (Looks a bit like a silhouette of a house, with 4 screw holes in the roof, a crease at gutter level and two keyhole slots.) I need one for my carrier (or measurements to make one up).
Carrier No.2 (or 22) is two U-section channels with steel angle spot-welded to the top at the correct spacing to take the 19 set (only). Two loose pieces of steel angle then fix to the set top (using the 6 tapped holes in the casing), The set fits to the carrier (with suitable padding on the steel angle bits), a strap holds it in place, as usual: fixed plate at left, adjustable at right, under the carrier, the power supply goes on its side (output connector to the left) on the set top - more canvas padding and the shorter strap under the steel angle pieces - lay the strap down before screwing them on, and the dog-bone links the supply unit to the set. Simples! <Squeak!>
Carrier No.2 is probably unpainted (tin-plated steel), the later ones (22) were painted green (or, probably brown) at the factory.
Four shock absorbers mount the carrier to the vehicle in the usual way.
Hope this is some help.
Chris.