Cheers for all the advice guys. I'll do it on the weekend and let you know how I go.
I noticed a little oil leaking from the exhaust too. Seems one of the bolts has broken off in the flange so I'm in for an exciting weekend of fixing bits and pieces.
I guess I knew what I was buying into when I saw the bike for the first time. She has had a very hard life. But still my favourite with two wheels. And a bit of work will bring her back to life.
Once again thanks for all your help.