https://www.antiqueradios.com/features/lacquer.html
Here is a link for you.
The mixture is 1 part shellac and 5 parts gas line antifreeze [methyl hydrate]
Just brush it on in nice even strokes with the grain. It dries very fast.. then you can lightly sand over it , to get any small bumps off.
I use a 1500 or 2000 grid sand paper.
If you do sand it a little and you see where you have sanded , don’t be too concerned: it will disappear with the finish coat of lacquer.
Dan in Calgary