Thanks Richard.
Will have a look at it later tonight.
By way of explanation the guy i bought the boat from came to do 2 or 3 jobs on the "subject to survey" list. The diesel boiler ,fridge and one or two other bits. He went to his car to get some tools and had an heart attack (honestly) . His two sons were with him so they called ambulance and had him carted him off to hospital. This meant the questions and queries i would have been picking his brain with was no longer possible. This kinda left me in the lurch as he no longer wants anything to do with the boat so thanks for sharing your knowledge.