I would need more information before I could help you more. Not very happy about the oil pressure light, though they dont run a lot of pressure anyway.
If the bike has been stood for a long time, you have to think that the crank sludge trap may well need cleaning out which is not a cheap job.
Drop me an e-mail at
chris.bushell@nourishengineering.co.uk and we can discuss off line.
Chris