I am doing some research on the history of vacuum cleaner production and marketing in Britain prior to the Second World War. I have found some first hand accounts by vacuum cleaner salesmen in the 1920s and 1930s, but not much in the way of paper archives - as none of the vaccum producers appear to have had their archives preserved.
I would be very interested to hear about any information on vaccum cleaner company staff magazines, manuals issued to salesmen, or other material dating prior to the Second World War.
Please see the following link for a Hoover item I put on the BBC's `History of the World in 100 objects' web-site.