Finally finished off the ambulance & base yesterday and am very pleased with the final result. I began weathering the model with heavily thinned tamiya flat earth then attacked it with VMS pigments mixed to match the colour of the base. I used VMS alkyd binders and universal weathering carrier to build up the effects with the pigments and also apply almost like a wash in places.
Then the figures and base had some attention with pigments before fixing everything to the base. The ICM kit is really nice to build and has great details. You could really go to town on it if you were so inclined. So another finished model for the bulging display cabinet and another build slot opened up on the bench!