Somebody here might have posted about this place before:
http://www.waldenfont.com/default.asp?sc=763&gclid=CNDA4oaizsoCFYdgfgod1REHpwThey have everything from Civil War (and before) to WW II era fonts, apparently as images on disk. I can see either printing out signs or gluing the print-out to thin cardboard and making a stencil. These fonts go really well with anybody's pre-50s layout look.