I seem to recall there was a good deal of ill feeling when some of the remaining 'Masters' (pilots & navigators, that is) were moved into ground tours from which there was little likelihood they would ever return to flying.
The story goes along the lines of: (a) no more flying pay and (b) you're now a warrant officer in a ground trade so get your badges changed.
Drifting away, the 1951 trade structure introduced the rank of Master Technician for those in the (mainly) engineering trades. However, other particularly skilled airmen in trades such as Equipment (Trade Group 18) and admin, could also hold the rank of Master Tech (and the lower ranks of chief, senior, Cpl and junior). In the 1964 trade structure this situation was abandoned but personnel 'wasted out' in the old ranks or until they were promoted. Hence at Brampton in the early 1980s, there was still a chief technician personnel admin clerk in the HQ.
O-D