That's a thing though, when MOT'ing a bus for example, the tester may open the engine lid to check battery security, but he has no requirement to check anything else. Of course, a competent, or nosey, tester may notice or check an insecure or cracked fuel line, but he has no remit to, and a fresh MOT means nothing in this regard.
In fact, someone buying a bus that has a fresh MOT may end up with a FALSE sense of security that they have a 'good to go' bus for a year. Someone may take a bus out of storage, get it MOT'd and be happy they can just crack on for the summer as long as it has fuel in the tank and air in the tyres ...
Anyone who has a 40+ year old vehicle should have a word with themselves and decide if they are capable and competent enough to run it themselves and if they have any doubt they should be employing a garage or mechanic, and not just for strict MOT concerns. Whether we have test exemption shouldn't alter this.
I genuinely think there is a much higher risk on our roads by the people who drive end of life bangers (15 year old motors bought with a bit of MOT to run into the ground) -Cars that are well equipped enough to provide high performance and comfortable enough to make the driver think that all is well, but can be absolute hanging death traps that need scrapping asap.