Hi again urich,
In October 2007 (when I jumped into Airliner modeling seriously), I purchased a bottle of "Future Floor Wax", a pack of #0000 steel wool, and small (1 lb) tins of Minwax Enamel Paint in Black, White, Red, Blue, Green, Brown, & Yellow, as well as a larger can of enamel thinner. (when you get supplies like these, it appears to be household up-keep & touch-up supplies which generally makes the better half feel proud that you're preparing for odd jobs around the house)
With these colors however, I can mix virtually any desired color and have used them on the 8 airliner builds since '07, still with a little over 1/4th a can remaining in each. I use an airbrush for broad surfaces and standard multiple sized paint brushes for the detailing.
(1) Buff with steel wool,
(2) mask & apply the paint (dry under box 24 hours),
(3) apply coat of Future (dry under box 10 hours),
(4) decal & weather, apply 2nd coat of Future (dry under box for 10 hours),
(5) gently buff with steel wool then buff with soft cloth.
It's old school, but it renders a beautiful, low-cost, and durable finish.
Later...
Frank