[TA Forbes]

Using shellac or grain filler is a good idea first. Or sanding sealer, but the sealer does not fill the grain as well.

I believe medium walnut is the color to use, over the entire set, but Ron is the expert in this arena. I would recommend using a dye based toner for the portions of the radio that used nice wood that you want/should be able to see the woodgrain through. Pigment based toner should be used on the portions of the radio that were made of lesser grade wood, like the base moulding. Another way to do this is mask the rest of the radio and spray more coats of dye based toner on those parts of the radio.