The factory layer will need a heatgun treatment (do a search on that) and the body may not be very suitable for a natural finish. Many MIM bodies that have solid colors actualy consist of several pieces of alder that may or may not sync up visually (most often, they don't), sometimes up to 5 pieces. I know for a fact that sunburst models have a veneer over them, so they are fine for natural but I'm not 100% aside from that on the other ones. I refinned a Midnight Wine MIM a while back that was hideous underneath the paint.
Official Fender Precision Bass Club #881, Gallien Krueger Official Club #921, N.Y. Bassists Club #52