Anyone Ever Replace Sleep Eyes in a Vinyl Doll?

[YellowCat]

I need your help!

I have one those vintage Edward Mobley squeaky cats with sleepy eyes (if you don't know what I'm talking about look it up online).  It's in wonderful condition except for the eyes which are rusty and moldy and everything I've tried will not get rid of either the rust or mold.

How do you figure out what size eyes you need to buy and how hard was it to get the old eyes out and the new eyes in?  Mind you that the plastic this toy is made out of is softer and more rubbery than pony plastic or your average vinyl doll because it is a squeaky toy.

Thanks for any help you can offer.