Nope, the bunker was empty, I tried to find out more about it but drew a blank.
Bowlander, I'm not sure if you wanted info about the specific bunker you stumbled upon, but have a look at this:
http://en.wikipedia.org/wiki/Royal_Observer_Corps_Monitoring_Post
They are still a relatively unknown part of the post world war 2/ cold war legacy. My father told me about them a few years back, and after finding the locations of them on urban exploration forums, I went and visited several with a mate. They're normally found quite near main roads on farmland, usually on a high point. The countryside is peppered with them, and if you live anywhere rural, you needn't travel more than about 5 miles to find one. Most villages across the UK have one. Sometimes they are just concrete squares in fields, other times they are in 20ft by 30ft chain link fenced off compounds, engulfed in 6 foot high nettles, having not been opened for 40 years.
The ones I've visited range in condition. Some being in fair condition, with nostalgic items like brasso, cleaning agents, mapboards with duty rotas's and exercise notes, furniture, and posters. Meanwhile others, with hatches wide open, dead sheep inside, flooded etc.
The most interesting are that a small percentage are still locked with original army padlocks, and since these things are never likely to be opened again, I am ever so tempted to go and do some investigating with bolt croppers, as these are most likely to be the best kept, and un-molested bunkers.
There are even one or two which have been preserved, and one in particular has been set aside in a museum somewhere iirc.
I still find it amazing, that these things are just left, completely accessible to the public in most cases, and they have never been demolished. They're just left to decay, and I wonder what will remain of them in 50 years time.