At first: Most of our Travellers (up to 1958) have a body number beginning with FL*11... the last 1 stands for synthetic varnish.
The term "synthetic" might tell us that a coat of nitrocellulose-based varnish (NC) has been used. Usually NC has been used until the late 1950s, later cars should have been finished with alkyde-resin-based varnish which has been used until mid/end 1970s. So this are the two types of paint to use for a restauration true to original.
Today, there are two other types that are used the most in the automibile-industry: There is the acrylic-based and the water-based product.
NC
Nitrocellulose based products have been developed in the 1920s and were the first "fast-drying" varnishes. Henry Ford had to deal with drying times of 48 hours before the introduction of NC products!

Alkyde resin
Also known as "One-pack" products. Replaced by Acrilyc in the end 1970s, because they haven't got much resistance to UV-ray (just have a look at red cars from the 1970s, nearly every one looks dull on roof and hood) The advantages of Alkyde are, it's easy to work with, you can coat large surfaces without creating spraydust in freshly coated areas (so it is used today for lorries, busses, etc.) and it's the cheapest way to get a respray. But the gloss level isn't as good as it is with a modern paint und it is not resistant to fuel and oil! Also the resistance to mechanical impact and weather is quite bad. Not suited for buffing up.
Acrylic resin
Most reasonable way to go. Known as "Two-Pack" system and the most common manner to get a car painted. A little more expensive than Alkyde, but better in every concern: Mechanical impact, UV-resistance, fuel-resistance, bird droppings, can be used coat on coat and it's drying very fast. Also not suited for buffing up. (You abrade the coloured pigments, so it is a quite fugacious gloss and you are likely to get visible traces when you're finished.) Easy to work with, the best compromise between price and look!
water based
Water based paints are the most processed in the industry today. Every big car company is being using them since more than 30 years. You have to apply a water based coat, the coloured coat, on the prepared surface and finish it with a coat of acrylic based clear gloss. Advantage is that you have a very small amount of solvents, so Mother Nature rejoices. Disadvantage is that its very elaborate to work with because you have to do the whole work twice and you have to make sure you have the right temperature and air humidity throughout the coating and drying process!! Professional use only. When it is used professionally, the gloss level is mirror-like and long-lasting because you can buff it several times and it will keep the gloss for a long time. Expensive and only way to go when you wish a metallic finish!
I hope this might help someone.