Leaking stop cock

[jjevershed]

We live in an old tenement and have a stop cock under the sink and above our front door. The one above our front door started dripping very slowly (noticed yesterday). I have tried turning the t bar tap and I don't think it is shot (although I have no plumbing experience! ). When the tap is shut off there is no cold water coming from the taps. The pipes to the tap is covered by wood. is this something i can fix or do we need a plumber? Photo of leaky tap in my albulms:
//www.diynot.com/network/jjevershed/albums/

 

[Burnerman]

It's probably just a leak from the tap gland, but whatever you do, remove that panel so the stopcock body can be seen.
John