I was a Staff Cadet and P2 Grade pilot in the days of Sedburghs and Mk 3s. In those days (late 60s) MGSP or Mobile Glider Servicing Party, a group of RAF airmen technicians, would tour round the gliding schools on weekdays carrying out minor repairs, plus minor mods etc, even Minor or Minor* services and all went well.
This all changed of course when 'glass' ships replaced the 'wood and fabric' designs which just seemed to plod on and on.
The 'glass' ships which replaced the older designs were 'off the shelf' but ask yourselves, were they really suited to Air Cadet gliding, which required the VGS' and the Gliding Centres (there were 2 before they amalgamated to form CGS) to get as many cadets as possible to solo standard in an efficient manner ie as short as time as was safely possible.
I have no experience of a Viking equipped VGS but I would bet this took longer than it did at a Sedburgh/Mk3 VGS.
So was it really a good idea to replace 'basic' gliders with machines of much higher performance? On top of this, take away the ability of the RAF to service, maintain and keep comprehensive records of these new aircraft?
As I've said before in this thread (and I'm rather surprised no-one has taken me to task over it) it needs someone to produce a low performance glider suited to Air Cadet gliding needs rather than an 'off the shelf' product meant for soaring and long distance competitions.