Re: Baltimore & Ohio early diesel lettering font
Jack R. & I put together the initial font and logo offering on the B&O RR Historical Society website 14 years ago. (Goodness, was it that long ago?!) I drew the "13 Great States" logo and Jack did the fonts. We scanned the original blueprints and used them as a guide for creating the digital versions. I've seen the "13 Great States" logo used on various model freight cars which is always tons of fun. Another B&ORRHS member, Kenneth VM, put together the other fonts on the page.
You can find them here: https://borhs.org/Logos/bo_font_logo.html
Hopefully they will be of use to you. If you have any questions, let me know and I can hopefully help out. I don't get to the Archvies as much as I would like (kids, job, house, etc. get in the way) but I'm only 30m away so I can run up there if more material is needed.
Researching & Modeling the Georgetown Branch of the B&O in HO scale