I'll add that through referring to Drones I had only visualised the quadcopters in use today which are plucking away at some of the jobs that used to be NPAS' bread and butter, though as discussed the prospect of fully autonomous drones with the real flight endurance and controllable range to completely replace helicopters in this space does seem a world away but I'd imagine there are plenty of companies working away at it. There is a drone project not too far from me that is trialling rapidly delivering urgent medication to two hospitals in the UK.
Like you say PANews, these are technologies that need to mature and prove their reliability and they aren't going to be instantaneously deployed over densely populated areas, the project I refer to above currently follows an exact routing for every flight that avoids any sort of housing at all let alone anything that resembles a town or city.
The difference in maintenance requirements you mention between the 135 and 145 leaves me even more bewildered as to why NPAS weren't at least tapping the RAF up about those 5 surplus Junos they had, seems like that could've been an easy win.