Re the Q plate, there is an old stigma attached as they mostly appeared on very DIY kit cars.
These days a Q plate car is generally worth a bit less than a normal plate, though how you compare is beyond me! I guess it is say a Cobra replica with or without.
The problem when the DVLA an old plate ...

I have had my 1960 mini taken off the road due to holes drilled in the boot.
They could not fault the EV, just the holes.
All the ideas and plans discussed on this thread will be of no use if the DVLA just ignores them.
I have a parliamentary petition on the subject and my MP has written 3 letters ...