Just checked DVLA and its now 78 which would make it rolling 40 years so I need to pay more attention to what year it is!

Tempus Fugit

Not a whole lot will change after Brexit.
Have look at Page 26 of the consultation document.
The UK (and the EU!) are still remaining part of the UN-ECE regularity framework.
So its the UN that sets the rules!
More info here: https://www.unece.org/trans/main/welcwp29.html

I cant see them retrospectively banning previously previously legal vehicles, it gets very expensive (for Governments/tax payers ) if they do.
Here are a couple of examples:
£200M (in 1833 money) to compensate slave owners, after slavery was abolished.
https://www.bristolpost.co.uk/news/bristol-news/taxpayers-bristol-were-still-paying-1205049
And almost £100M to ban handguns
https://ukshootingnews.wordpress.com/2016/08/02/britains-pistol-ban-cost-taxpayers-almost-100m/
But of course they could just make cost of ownership more expensive, as some cities are now doing.

"Diesel Gate" is even mentioned by name in the document, with recent raids on BMW etc, this is not going away anytime soon!

Either way NOx and particulate emissions are not good, but it could be resolved by rules that limit the miles driven by more polluting vehicles and allow them to stay on the road, who knows, I certainly dont!

Agreed, I think you could be right about limited mileage, it would be an easy fudge. I've just been looking at the revised MOT requirments coming in, some worries there too. Most of it is eaither sensible or aimed at modern cars, but there are fail on "leaks that could harm the environment" which very well descibes my Perkins with its rope oil seal. Fortunatly mine is old enough to be exempt but it still makes me nervous. Kicking myself now as I sold a 1980 Petrol Mercedes when the historic rule was fixed at 1973 before they brought in the rolling 40 years rule and diesel was trendy. Now that 3.8 ltr pertol V8 would be looking rather attractive with no emissions check MOT or tax. They could deal with the older diesel issue by upping fuel duty, could be a time to buy 1979 petrol Series.

Agreed, I've been thinking that it is likely that gov will bring in a very restricted mileage on classic, vintage and veteran vehicles. They wouldn't dare to drive them off the road altogether - not for a good few years yet anyway... Probably a bad idea discussing it on here, they do monitor these sort of sites and we don't want them to get any ideas.

I firmly believe that all this is linked to the UN's 'Agenda 21' and 'Agenda 2030' initiatives.

You are right to give a "health warning", normally I bear that in mind took eye off the ball.