to thebears
 

I contacted apple and they told me I need this model disk for a macbook 4,2.
Hope this helps and is not too old.

So call Apple if you really need to know which restore discs work for your machine, give them your serial#, and they will tell you what you need.

And it is fine to sell the grey OEM discs, it is the white ones apple specifically lists "not for resale."