Thanks for all your help and advice, I think that I am getting to grips with it now. Found your tech advice page and followed what it tells me. I did the compressor checks and it is weaker than a pump for pumping up a child's air bed. Hold it about and inch from my face and all I can feel is a gentle breeze, no problem holding my finger over the outlet. When I disconnected the blue pipe there was no air to escape.
So it's a new compressor then? I see that it has been rebuilt once already so I feel that maybe it wouldn't be wise to do it again.
Depends. Reckon he it can take 2 or 3 refurbs as long as it isn't vibrating madly or making nasty noises. You need the teflon seal and cylinder kit. Otherwise have a word with @kurtjohnson10 and see if he has one kicking about he can let go.