This Birmingham, or perhaps Coventry-based company had a very good reputaio n for building reliable lightweights, and produced some very respectable to p-of-the range frames until some time in the 50s/60s when they were taken u nder the SUN brand which in turn became part of TI-Raleigh.
The Ebay frame must be from the 30s, at a time when very many sporting ligh tweights would use Resilion cantilever brakes. When these were not fitted i t was quite normal to build at least one wheel, usually the back one with a hub brake. The bracket on the L/H chainstay is to provide a fixing point f or the security arm on the hub..not for a back-pedal brake.
I can't ever recall seeing such a brake in the UK in the 40s/50s/60s..proba bly not until someone started importing those 20inch wheeled folding bikes, called ROG, form Yugoslavia or Poland or somewhere in the 70s
Norris Lockley....Settle UK