The differences between early and late ambulance body's are mainly shown in the 'Filler-Cap' area.
Where the early model has a small 'Filler Cap' the later type has a bigger 'Cap'  with a cavity  to allow  filling with a 5-gallon can w/o a spout  
The early models had 'DODGE' nameplates on the radiator cover the later had none
There are models with an 'Air-intake' and without one (***)  
Ambulance body's were used in different roles, Police, Signal Corps, Coroners,  Maintenance etc, so , the ones in existence today may also be seen in different guises.
Left side
Dodge  T214-WC54 4x4 Ambulance 3/4 ton
Note the wheels , they look like the prototype
Step folded in
Step folded out
Deep fender rim
Shallow fender rim
Wheel cover
Note the difference in trim (wide/small)
Wire connector
Hook for stretcher, fitted on both sides , stretcher was hung in the middle on straps.
folding benches seating 8 wounded men.
Cover on left-frontside of rearbody , for mounting an aerial ?? or does anybody have an other idea ?  
Reardoor right  inner detail
Covered hole on the left front
Note inside door detail and sealing strip between rearfender and body
The above interior looks more like a mobile first-aid dressing  post than a normal ambulance shown  under
Big crosses
Small crosses
Late model
Early model
Detail instde left reardoor
Spotlight details
^
I
The Dodge WC54 ambulance is one of the many variants
of the 3/4 ton 4x4 truck .
To mount the rearbody , abel to carry 4 stretchers or 8 sitting wounded, the chassis had to be lenghtened .
Accordingly  the wheelbase changed from  98 " to  121"  
.
The Ambulances have extra shocks
Sirenes
To return, klick right mouse button.   Wait a few seconds and you will return to where you were.
(***) From my info I could only find that 'early' types did not have the air-intake, but Dennis Buijs from the Netherlands let me know that his 1942 model WC54 also has one.
Althou shown here under a non Ambulance model