Someone in the past week or two posted a formula for the carriage paint from Home Depot.  Could you please post it again in this thread.  
When you do I will add a link to the FAQ's to this post so we can find the formula when we need it.
Here is the original formula from The 1864 Field Artillery Tactics:
Proportions are given for 100 parts by weight
Black Paint
Lamp black  28 
Litharge  1
Japan Varnish 1
Linseed Oil, boiled  72
Spirits turpentine  1
Grind the lampblack in oil: mix it with the oil, then grind the litharge in oil and add it , stirring it well into the mixture.  The varnish and turpentine are added last. The paint is for the iron work of carriages.
Olive Paste
Yellow ochre, Pulverized  68
Lampblack  11
Boiled oil  37
Spirits of turpentine 0.4
Make a thick paste with the Ocre and oil, in a paint-pot, and with the lampblack and oil in another; grind them together in small portions, and keep the mixture in a tin vessel.
Liquid olive color
Olive paste  61.5
Boiled oil  29.5
Spirits of turpentine  5.5
Dryings  3.5
Japan varnish  2
Stirred together in a paint pot.
I think I will just go to Lowes and get it mixed.