Any chance of Series A fonts? 
yes. I will program that in, as I do have a copy of FHWA's specification from 1966. (Just about the end of the line for Series A.) I also will have 1926 FHWA (block font) series B, C, D, E, F* and assorted custom fonts like Mass, New York and Maryland.
*Square A was not ever used on shields, I don't think; it is significantly narrower than Round A, almost to the point of being illegible. Round B, C, D, E, F match up exactly in width with their square predecessors.
anyone know of a good free program that converts vector graphics to fonts?