When you get there, look at something like these. Thinning One-Shot striping enamel to work correctly in them might take a fair bit of experimentation, but I'm 90% sure it's possible. NOTE: The color coding denotes tip size, not ink color.
One Shot will not flow through a Rapidograph Technical Pen, they are made to flow illustration ink only. They are somewhat of a pain to clean with ink, I cannot even begin to imagine cleaning enamel paint out of one. I have uses some of the liquid watercolor paints in them, but at $20 plus per pen I wouldn't feed any other paint through it. They don't like India ink either it's too grainy and tends to plug up then pen nibs.
I gave a rather long winded but accurate answer to someone asking almost the same question here.
This was essentially the same question you are asking. For model car leer rearing almost any enamel brush type paint will work, the little Testers jars are about the same consistency as One Shot, Ronan, Little Daddy Roth striping and lettering paints. There are a few old Signwritters and Stripers that hang around here, if you ask nice we could provide a little guidance.
While you are looking up lettering fonts look up "Snap" it is the quick informal lettering style used on a lot of race cars and signs. At least that's the name I've always heard that style referred to. There are tons of font styles on the Net, you should have no problem finding more than you need out there.
For what you are lettering you might look at a "Rigger" watercolor brush, cutting the tip as described in the other post. Riggers are named so because they are used by watercolor artists to paint ships rigging.
Very nice indeed! Very plausible, looks like an "Old Lady car" that someone got ahold of and turned into a sleeper. Gray Baskerville and a few other Hot Rod writers used to call them an "Uncle Daniel", they also called well preserved stockers that too. Sort of the best of both worlds a car that looks like stock yet goes like stink! Did I mention that I really like your model! It's cool.
There's an older guy who shows up at the local A & W Cruise night who almost specializes in sleepers. He's had a '57 Olds with the J2 Rocket Motor it still had the stock upholstery covered by clear vinyl seat covers, an almost everything delete '55 Fairlane with 428 Super Cobra Jet, currently has a sorta faded green 61 Biscane with dog dish hubcaps, duel 4 barrel 409 in it that was supposed to have come out of a "well known" California Super Stocker sometime in the early '70's. One of those guys you look at who doesn't look like a car guy at all or like he would have the money to play the car game at the level he does. All his cars are quiet almost sedate sounding. Sleepers are and will always be cool!
Whenever I drive my Cooper-ized Mini to a cruise night he almost always parks by me and talks my leg off about racing Minis in the '60's, he knows what he's talking about too. He always tells me that a real Mini Cooper is the Fastest Ten Feet Money Can Buy!