Personally I don't think that was worth £30. That's a Klingenthal-built cheapo box from the 1930s, and they are almost all very low quality and in very poor condition. They suffer from all the standard old accordion problems such as crumbling reed wax, curled leather valves, out-of-tune reeds etc., but as they are lower quality than West German and Italian instruments they also seem to be more prone to other problems, such as sticky/warped keys, rusty bellows corners, peeling celluloid and so on. Essentially, you could pay several hundred pounds to get one repaired, and still end up with a low-value, inadequate accordion. I've had a few and none of them have been satisfactory instruments, and I wouldn't recommend anyone gets one as their first box, particularly without actually having a go on it first.
Where in the UK are you based? There are a few shops here and there that will sell good quality instruments in working order, and there are bound to be people prepared to lend you an instrument if you want to try getting to grips with the accordion before you commit to buying one!