I had business in Fayetteville today, so finally went by the University of Arkansas library. I was looking for old MODOT/MHD annual reports, but stumbled across something else while I was there: a 1950's Arkansas MUTCD. I took a few photos, but some of them didn't come out, so I'll have to go back in a couple weeks and try again.
(https://scontent-dfw1-1.xx.fbcdn.net/hphotos-xap1/v/t1.0-9/11800348_10206127545060060_5381818985006606397_n.jpg?oh=5574480cffee44a7b75c3c3cde14fe28&oe=56579571)