Ah, I see. Ideally what I would do with that is to check all of the wiring, all the points that have been soldered/crimped/etc, look for corrosion, damage, leaks in the caps (depending what they are) - that sort of thing. If it seems good it's probably fine, but like you say, things break all the time and it's not a bad idea to enclose it all.
A good (ie: proper) case for that might run £15-20, though, mind you. Might be worth it just to go for something new instead, depending how handy you are and what bits of scrap or tools you have access to. Difficult to say, mate. I'm cavalier as the next guy, and I'd have no problems powering it up to test it, etc, but I personaly wouldn't leave any electrics like that running in my gaff unsupervised for long periods of time. It all breaks eventually and you don't want your place burned to the ground on account of it.