I have a closer look at the shield below.
Now, US 62 does go through Texas. However, when you look at the highway sign gallery experts at AARoads, Texas never used that style. So, that makes it seem likely that it wasn't ever on the road. However, there's something about the design that is unique and not found that it could certainly have been a test sign or briefly used. Doing some additional research, I did find another angle of the sign from the Rum Boogie Cafe's website.
|(Rum Boogie Cafe)|