Stanley Steamer received his name in 'Dragon on a Pedestal (1985)' having previously been the Gap Dragon. I recall becoming aware of Stanley the Dragon about the same time I became aware of television commercials for a similarly named American carpet cleaning company. Is this just happenstance or is there a connection?
Stanley Steamers was reference a to Stanley Motor Carriage Company (1902 to 1924), it is possible/probable that Piers was exposed to this name in his youth.
The carpet cleaning company's web site nor the Wikipedia article for it mentions when the company revived it's name. The company site lists a 1947 start by a person who's name has nothing in common with the present company name. While this company uses a slightly different spelling (I have chosen not name the company or provide links, if your not aware Google will point you right to it) phonetically they are identical.