I am not sure that a history of plodding around the beat makes a candidate for Air Observer any better than someone that has a history of e.g. taxi driving.
The ability to think outside the box, be flexible, have a will-co attitude, have mental dexterity, etc, etc is more important. I would rather see a highly trained Police Officer doing his job on the street for a full shift rather than sitting around for more than half it waiting for the phone to ring in the office.
Just a point of view.