.As it happens, I think MOT exemption is potentially a bad thing (So I read, so does Ron Gammons, the well known MG specialist and competitor). It will only take one accident, for people to start assuming old cars aren’t safe. Because most people’s experience of old cars is of old bangers, there is already a common assumption that most old cars can barely go.
It would be of far greater benefit if we had a level playing field, based on an accepted definition/age (I think rolling thirty years would be fine), where any “Benefits”, derived from historic status, were enjoyed across the board (It might put to bed these stupid debates about whether my 51 Plate Vectra is a classic car, as the answer will be “If it’s still about in twenty years, yes it will be!”). As to MOTs, perhaps there is a case for requiring them after a certain mileage or every three years, whichever comes first. I would suggest applying this across the board, as surely ultra high mileage cars need checking more often than one a year, whilst the little used, fine weather special, probably doesn’t need checking every twelve months.
The other thing, it is, as I said, a complete misinterpretation of the classic/modified scene over there...
Too late! im already there 
ive been looking forward to the day the EU implodes since black wednesday 20 years ago.