Tockwith Training:
Just rung that number, lady on the phone said what you mentioning is correct.
She is nice and very well informed, isn’t she 
- must try to remember her name - she recognises my voice now and says “hello again ROG from the trucknet site” 
- the DSA probably have my number giving an ‘alert’ when it comes up 
Tockwith Training:
Seems a bit strange, but if that’s the rules then fair enough.
When I think about it, it’s no different than say a HGV class 3 driver who passed the test many years ago and has not driven one since the test - both have a licence and neither have passed the modern LGV test in it’s current format.
To my mind that makes both the C1 on grandfather rights and the HGV class 3 driver mentioned above at the same level in regard to the driver cpc.