The Southern was rather particular about how its rolling stock was painted and lettered. It produced stencil drawings for different car types and updated drawings as lettering standards changed. It’s important to understand that “stencil” drawings were only intended to show where individual stencils were to be placed on the equipment, each and every stencil; monogram, dim data, road names and numbers, etc. had their own drawing to be used to cut the stencils.
Although the different sizes of the post 1960 “block” lettering were proportionally different (i.e. same design, just different sizes) the earlier “Roman” style letters had individual drawings for different sizes. Things such as letter thickness, width, style of serifs and spacing could vary. Early (hand painted) passenger car lettering was quite ornate. Later “block” style passenger lettering, sometime called “streamlined” lettering was much simpler.
(I have mentioned before, the Southern did not have a lettering standard when the 1941 “Tennessean” and “Southerner” were being built at P-S. Southern simply used the same 7 inch lettering EMD had developed for the E-6s.)
Quite a few lettering drawings, the round monogram (never called a “logo”!) and placement drawings were published in the SRHA 40’ and 50’ (1938-1982) box car books. The 50’ book is still available from SRHA (maybe 12 left?) The 40’ book is long out of print but a new version that includes all of the various 40’ rebuilds is about 60% done. (When time permits, we will publish a list of all the drawings we have scanned. When we get the new networked drive set up, we will make digital versions available at nominal pricew.)
PS About the best Southern decals produced and sold today are from Hubert Mask at Mask Island. SRHA has provided Hubert with detailed drawings of many of his decal sets.