There are a number of videos on this, one in particular that I can't find.
It showed them using a 2 part fast dry lacquer, the 2 parts being the lacquer and the other part being the hardener.
A two part auto body clear coat would work well, you can use it to fill the damage, allowing each application to harden fully before applying more layers.
(and by harden fully, 3 weeks at least)
Applying too much at one time does not allow the thinners in the clear coat to escape and you get trapped air bubbles and uncured "soft" finish.
I've used clear coat with great success, it's easy to use, but it's expensive. (you can't just buy a small amount, the hardener will go to waste before you can use it up)
After filling the damage, carful wet sanding has to be done with finer and finer grits, being carful not work through the original finish.
Starting with 400, then to 800, 1000 and finally to 2000.
Be carful with the 400, you can quickly remove quite a bit with that.
You may even start with 800, depending on how much there is to remove and how bad the damage is.
Usually I use an air brush to apply the clear coat because it does set up quite fast, but in your case, a good quality artist brush should work.
I finish up with 2000 grit and then hand or machine polish with 3M Finesse-It
I would like to see a photo of the damage.