Thanks everyone shes running fine and nearly good to go for an MOT.
I had to take the carbs off and give them a good clean as Rob suggested.
I found that the main jets were all blocked which a good squirt of carb cleaner and a bit of phone wire sorted.
And the needles at the top of the carb which summit slides up and down on (sorry i don't know the correct name for them) were all covered in nasty golden residue, so cleaned them up.
I don't know much about carbs but with the help of the manual that I found on this site I managed to strip, clean and put them back together one by one.
I also treated her to a brake fluid change, oil and filter change, new plugs and new coolant after a flush.
I then (after charging the battery) Got her going again  
  
  and with a few high revs and back fires she started to settle down and run nicely.
She still won't tick over below 2000 yet but I think it's something a shot of redex and a good runout will sort.
Thanks again everyone for your help.