I used the liquid varathane method on my 1976 #Hang Glider. Came out great.
Don't use a Sharpy marker for black lines. It will run.
I used a plastic spoon to add about three drops at a time. Many layers. No masking, just let the varathane level itself out.
Light sanding, light magic eraser for cleaning (easy does it) and some color retouching --- then at the end sprayed on clear varathane on the whole stripped playfield.