Unless I am very much mistaken it says 'Royal Enfield' on the tank?
And is very similar to this 'RW' model shown for sale here: http://pembrokeshireclassics.com/shop/product_info.php?cPath=61&products_id=272&osCsid=97fd22d3cbaa3b545645edd396322507
But may not actually be a two speed RW, as there does not seem to be any form of hand gear change lever on the bike shown above? Although I'm not sure what the double pedal outboard of the clutch does, but Royal Enfield were one of the first manufacturers to use a foot change lever apparently? So it may be some type of gear selector?
http://www.ohtm.org/1922enfield.html