Have a look through some of the restoration threads here and at the rsoc.co.uk - can your Dad weld panels? Can you weld panels? Are you confident you can source parts that are no longer available from the dealers?

Restoring an S1 can be a MAJOR tast. I would get some pics of it and post them here so we can take a look and advise you on what needs doing and the cost of paying somebody to do them if you or your dad aren't capable.

Don't forget it will need paint too - restoring a car isn't cheap at all - you could spend £1000 on buying the car and another 3-4K on the restoration unless you are doing absolutely everything yourself.

Sometimes it's easier to buy a car that has already been professionally restored.

Don't forget also that if you "bodge" the restoration the car will be worthless too - especially an S1.....

Not wanting to put a downer on the whole thing - just trying to make you aware that restoring any car is a major task not to be taken lightly....