A quick google tells me Lockola was mostly a lap steel brand (associated with Magnatone?), but they had a version of the Supro Belmont too (images from ebay):
so there's the big 3
National
Supro
Airline
plus
Tosca (3/4 size plainer versions of cheaper Supros, slightly different body shapes)
English Electronics (Rhythm Tone, maybe also Dual Tone
Silvertone (one and two PU Artist model)
Oahu (early 50s solids, like the early electric solid Nationals)
Lockola (Bemont variant as shown)
any others?


 
 - thanks for posting that link - Dwight, eh?
  - thanks for posting that link - Dwight, eh?