PANews
I doubt whether the "wrong colour" would put off a police ASU that was urgently in need of a spare. An available MD902 in police fit is a rare commodity at the moment and I'm sure would be lapped up whatever the colour. There are still some ASUs that don't use the now traditional blue/yellow colours.
Temporarily covering up the "Air Ambulance" sign is an easy process which PAS has used many times before. The old PAS BO105s continually flitted from one role to another with the use of stick-on signs.
With regard to lack of time and engineers, the removal of the belly role-pod is easy and takes little engineering time. It is just a case of "disconnecting a few wires and undoing a dozen bolts"; PAS Projects Department designed it that way. The removal of the Nitesun is even quicker.
The role-pod and Nitesun would have to have been removed for the re-spray anyway, so why spend extra engineering time in re-fitting them unless they wanted to use them again?