If you are interested in the REA and Milk Cars these booklets maybe something to find.
In the beginning of the REA (Railway Express Agency) booklet you will learn. That years before there was a "REA" there was in fact the "American Express Railway Co." And before I bought Lionel's car pictured below verified paint and lettering. So Lionel did a great job here.
The text goes on "Original lettering scheme as handed down from American Railway Express." "The body color was a deep green commonly called Pullman Green." "Lettering was gold and mayhave been (at various times) gold leaf, bronze (metallic) gold paint or imitation paint (buff)."
The only thing Lionel's cars scale about 43/44-feet long. Where in fact the interiors were that long with exteriors being 53/54-feet long.
Now the "Railway Milk Cars" booklet is one of four volumes which regrettably did pick up at time. But this one has pictures of various Borden milk cars and Borden milk tank cars.