From memory oil light shouldn't be on?!! Been a while since I drove mine but should go off straight away. Has it got an oil pressure gauge?! Cos then you can check pressure from cold and see what it drops too once warmed up.

If they don't mind you doing it and you have one check the compression on all cylinders asthen you know where you stand with that.

As said check for rust everywhere!! Especially where the beam mounts sit, doing a resto on mine and had to cut that whole section out as it has collapsed