Radio finishes of 30s & 40s

I was watching a program that talked about the properties of shellac and ways to improve old finishes.
Shellac comes from a Beatle. It is made into flakes. If the flakes are too old then they will never set and remain stickey.

To remove old Shellac which is dark brown or black use denatured alcohol and #'400 steel wool.Then sand to remove uneven surfaces. If you have deep scratches then apply wood putty for a filler. Sand after the wood putty has setup.

If the original wood is lighter in some areas, then apply the stain after sanding and cleaning all the dust with a cheesecloth.
If the wood still has areas that still remain lighter than the rest, apply more stain.
You can use stain with an artist fine pointed tip to apply to minor scratches to help hide those.
Shellac not only protects but enhances the wood grain, so you can add depth to the wood grain so it will almost glow with several coats. Shellac comes into colors the most used is orange or also called Amber. Then the final coat applied can be either a Satin or gloss. Or a mixture of both to get a semigloss finish.