The value of testing older equipment is not so much to romanticise, but to get an idea of whether it makes sense to replace them with something of more recent design, or not. My hunch is that for example modern amplifiers may include more modern manufacturing technology but do not necessarily deliver better sound quality, since many older designs were already good enough.
Here in the Netherlands, and I am sure in the UK as well, Quad amplifiers have always been very popular with those who were looking for sensible designs that delivered excellent performance for a quite reasonable price. Since they were largely built from discrete components they can still be maintained/refurbished without too much difficulty , so there are still many around. Therefore, the question is whether it still makes sense to use them, or do more modern designs offer increased sound quality. I am sure the same question can be asked with a number of North American or Japanese designs. My parents for example had a Luxman R50 receiver: how does if compare with more modern designs?