Duco
This cleaner probably dates from the early 1960s, manufactured by a company called Siroma who did not sell cleaners under their own name as far as I know but manufactured them for a variety of companies like department stores - which Brown Brothers was. I am sorry to tell you that, at the time, they were known to be very much at the very cheapest end of the market.
Although reasonably rare there have been at least two on ebay in the last couple of years, I have one (I was the only bidder) - not sure if the other sold or not. It would perhaps have some value for a collector but this was by no means a luxury or exceptional cleaner, although I will grant you that it looks in good condition. Does it actually run?
You best bet would be to put it on ebay at a low start and see how it goes - and be ready to post it (should be no more than about £15.00) to widen your market.
good Luck
Al