I've an old Holloway machine with 2 brushes and feed. Similar design but heavy, it must be at least 20 years old.
The Holloway was purpose built, with chemical feed to the brush. Excellent design, but mainly brass and chrome, making it a bit heavy, none the less, used it quite a lot in the past, but forgot about it recently.
There is an 11" bonnet mahine I'd seriously considered importing a year ago, but would have been around the £500 mark, which I thought might be more than market would stand. It would be very fast on suites and stairs.
rob