The Silver Castle chain was another White-Castle-esque hamburger chain, one of the many that popped up in the ’20s and ’30s. Think White Tower, Little Tavern, Krystal, etc. According to this source, Silver Castle was founded in 1936 and had locations throughout OK and TX.
The interior shot, with its barrel roof, looks very much like factory built diners of the time, and rather unlike the squat castle-shaped building pictured on the restaurant china on the link. Some White Tower locations were built by Valentine, like this one, formerly in NJ. In this era, even Kullman got in on the game, producing a castle-turret styled dinette to cash in on the rising popularity of such establishments. The question is- is this Silver Castle location- shop no. 13- an on site construction with styling influenced by what was coming out of the diner factories of the time? Or did they contract their construction out?