To take your points in order Skidkid...
I doubt whether the "wrong colour" would put off a police ASU.
Wrong colour should. Thats why they are blue and yellow - a Home Office requirement after all. Lets call it a 'deterent' to using KSSH then. The Met wanted to retain the difference represented by the 'jam sandwich on white' of their AS355N's but were over-ruled - as were Western Counties who wanted a snazzy scheme for their EC135.
Yes, if there was an urgent need of a spare it might be used but as I would guess that KAAT want it asap they might be displeased if PAS were to just put it back together for another operator. Hardly good customer relations when that customer has agreed to await the completion to a set timescale. Anyway, although I am not in possession of the work sheets I would expect that very soon KSSH will not be an MD902 in police fit, rare commodity or not.
Yes, there are still some ASUs that don't use the now traditional blue/yellow colours but that is mainly because their aircraft have not been repainted since new.
I am not arguing about the removal of the belly role-pod being easy and takes little engineering time. BUT.... if what has to be done to KSSH is simply "disconnecting a few wires and undoing a dozen bolts" then why is it scheduled to take a month? If it takes a month to de-role to ambulance then perhaps it takes a month to re-role it for a 'police spare' ? Spare aircraft by definition need to be capable of multi-tasking, air ambulances do not.
I assume [dangerous word I know] that to occupy themselves for a whole month [when the paint job is already done and dusted] that in addition to some level of service they will be extracting all that weighty gear out of the by the back door and all the EMC causing police role cable ... less the searchlight as they clearly have a use for it. All about weight, payload and performance.
G-KAAT was never to my knowledge dragged back from the customer to serve as a police spare by PAS in seven years. The Wiltshire [dual-role] aircraft is a different kettle of fish and that is occasionally dragged back to suit PAS. Also I know PAS have occasionally prevailed on customers to use their aircraft by arrangement as a demonstrator, the static park at Helitech showed examples of that. But that is not exactly acting as a spare for another customer.