Ste, which bit was making the noises??
Cos looking at your pics, while the 3-pin plug looks decidedly suspect, the other end looks like a bog standard kettle lead plug. I acquired one of those miniature 3-pin plugs when I bought a USB doobrie for my old IDE hard drives, first thing I did was throw it, and got one of the 3 million kettle leads out of the box, used that just fine.
If it was the brick itself, it could be a little more tricky, as that's not a particularly standard looking connector on the end. Maplin may be an option though,as they do assorted power supplies with interchangable tips, and aside from that, it's just a standard looking 240v to 12v transformer.
Jim