Cleaning stonecast figures?

[AngelofDeath]

I have recently purchased some Pendelfin figures from a car boot sale. They are painted stonecast figures. The previous owner must have been a heavy smoker, because they are all yellowed and stink of cigarette smoke.
I have tried cleaning them with a soft cloth and some soapy water, but it isn't removing the stains. Is there any way of cleaning them without damaging the paint?

[carrust]

You could try Libnet furniture restorer. This is a meths based product that lifts grease & grime off wooden furniture without damaging the varnish. I use it on wooden balustrades & hardwood doors, & I apply it with very fine wire-wool.