Headphone repair/modification advice

[Viral_Jim]

I have an old pair of B&O A8/Earset headphones knocking about, but the cord has become partially detached where it needs the headphone body and I get intermittent sound in one ear.

I'd like to get the wiring replaced and an in-line mic added for taking calls on the mobile. Anyone know of a midlands based (or alternatively mail order) company that can provide such a service?

TIA