In some ways this is truly horrific. The government has chosen to ignore all their own evidence, and opinions expressed in the survey (in which I did express my opinions, not that they were even noticed), about the inevitable reduction in safety. They go on about most, or maybe just some, of the over 40 year old cars being well-maintained, but their own wording clearly demonstrates that there are some significant number which are not. and as pointed out by some respondents, the worst offenders may be business users.
There are some indications that the next move will be to deal with all those who have dodged IVA. I suspect that those who have illegally modified their monocoque, which includes flip fronted Minis, and many otherwise good engine transplants, will soon be in danger of having their cars crushed. That actually is not before time, action on such things (excluding well-engineered engine transplants of course) is long overdue, but it will catch out people who have done genuine safety modifications too. Many. who have done well-engineered modifications, will be forced to continue to have MOTs for ever but out and out bodges which are not glaringly obvious but downright dangerous may become MOT exempt, and that is not right.
The cut-off date should not be a rolling date, as there was a very distinct change from nasty, evil-handling cars with poor brakes to cars that were satisfactory to drive (leaving aside certain German brands...) in the early 1960s (driven by the Mini and everyone trying to copy its advantages). That is a fixed point in time, and should be seen as such, and nothing at all to do with a rolling date. I would have suggested fixing it at 1970.
As for the guff about MOT testers not being able to test old cars, the ONLY car made since 1953, till 1959, that was so remote from modernity that it would challenge a tester was the E93A Ford Pop. Note that it ended production in a very significant year, 1959! Its replacement, the 100E range, had McPherson struts and was quite nice to drive, as I know at first hand. But other cars of the 1950s and even late 1940s (Moggy, A35, Morris Oxford, Hillman Minx, Ford Consul/Zephyr/Zodiac and many more) had made the transition to independent front suspension, and in some cases, rack and pinion steering, and would be testable by a modern MOT. Speed came, in relatively cheap cars, with the Triumph Vitesse in the 1960s, then the 1600E Cortina, MGC (bit of a dud due to understeer), various Jags including E-Type etc, and then the early hot hatches, all by 1970, and then we are in the modern era, with Volvo initially in gthe lead on secondary safety. Roughly speaking, others may wish to express their ideas about when things became "modern".
Apart from my grumbles about the intent of VOSA, DVSA and the government, I strongly recommend that everyone puts their cars through an annual MOT, even if not required to. It doesn't guarantee roadworthiness (the MOT never did, despite what some people imagine) but it is an extremely useful way of checking for the sort of silly human errors that anyone can make in their maintenance procedures. And don't say that you never make mistakes, it is a fact that we all do! I know some of my errors and omissions which the MOT tester spotted.
Someone pointed out in the contributions that properly using a car, any car, helps keep it safer because things like brake cylinders tend to seize if left unused for too long. That is a very sound opinion, and I do wish that some people here would use their Minis a lot more to help keep them in good order. It often happens that a brake failure comes within a week or two of putting a car back on the road. The monthly comics often advise about laying up a car and bringing it back into action, but they invariably forget about the brake and clutch hydraulics. It looks like the Mercedes plot has failed in the UK and there will be no limit on annual mileage (it is a derisory amount in Germany), so use them while you can, preferably as daily drivers. Have fun!