The 1913 pictre could well be the same model, but, BSA stopped using the block brake principal on the front wheels in 1912. The system worked okay for a while, but, was comparatively useless in action, in fact a couple of minor accidents were directly atributable to the poor effect these brakes had at any speed. I suspect the pictured bike was registered in 1913, but is actually a 1911 model, sold at a later date, maybe even abroad. By 1913, all frontbrakes were of the banded type, same with the rear as well, these were first introduced for the 'mass' market in August 1912. The block brake, which looks almost invisible on a lot of early bikes, quite often stripped the thread of the bolt, mounting it to the frame/forks, due to the forward friction of the block on the wheel rim when applied, okay on a bicycle, but a 3.5 hp motorised jobbie was an entirely different kettle of fish, thus evolution carries forwards all the time..