The result is quite shiny. There is no visible yellow grain. The slightly silvery spots that I damaged are almost not visible anymore, thanks to the added yellow color of the shellac. There are a couple dust spots visible, if you look: perfection is not of this world. But the good thing about shellac is that you could sand the top again a little, and apply more shellac - or just do that without sanding. The alcohol dissolves the shellac, so you can always add new coats.

Courtesy of @Pelicram ❤ : Peli's Shellac Rescue Formula aka The Cowboy's Delight. This will help bring back a deeper black color shellaced panels which have been yellowed and damaged by UV over the years. With enough elbow grease it will remove the old shellac completely but it takes a very long time and you're likely to damage any decals present on the panel. In most cases the procedure described below will be sufficient to restore the appearance to an acceptable level. The recipe: 70% Light machine oil. 30% IPA (Isopropyl Alcohol) or White/Mineral Spirits. Ideally use an oil that is dissolved into the IPA/Mineral Spirits, if they settle into separate layers make sure you shake the mixture thoroughly before applying. Mix the oil and solvent in something like a dropper bottle or similar vessel for convenient application. Clean part with Fulgentin (Or general purpose cleaner of your choice) and wipe dry.,Apply oil/ipa mix to part and rub in lightly with clean microfiber cloth or shop towel. Use plenty of the mix, it should not feel dry.,Wipe with microfiber cloth after 15 minutes to get rid of any excess.,Do not apply any kind of wax (like Renessaince Wax) afterwards, from my testing it will bring back the haziness.

Use kerosene or mineral spirits to clean the machine. I wouod go with kerosene to be honest. Then redo the shellac finish with french polishing. This is heavy documented with old sewing machines as they use these gold decals that f becomes silvered when water or cleaning solvents touch them.

I only used Turtle wax on the paint. You can go over the decals provided you don't polish and put too much pressure on them.The nickle was done with a generic metal polish.