As someone who has hand lettered vehicles for over 40 years, I will suggest lettering quills for brushes, One Shot or Ronan lettering enamels for paint, and for reducer, I use Dupont 3812 enamel reducer. A lot of people will tell you to palette your paint using a phone book, I strongly disagree, flat paper can pull fibers into your paint so use a glossy magazine. Practice on some glass as when you are done you can wipe it off or let it dry and scrape it off with a razor blade.
Lettering is not as easy as many think, very few people pick it up right away. To letter a 1/25 scale model is WAY harder than 1:1. If you need more assistance, PM me.
This was all done with One shot and the numbers are 23K gold leaf.