Yerp, and rear seat belts. If they've been removed, then they can't be tested, therefore cannot fail
Although that might have changed in recent years. I remember it being a sticking point for track day cars at one point.
As far as roadworthiness goes.....you could have different brands of dampers, springs and tyres on each corner and pass, so long as they're not leaking, snapped or bald
I keep hearing a rumour about 2 year MOTs. I can only imagine that will apply to cars below an age limit, otherwise all manner of knackered sheds will escape the net. It does make sense though because the annual MOT started in 1974. Cars made since 1974 have changed somewhat