I grabbed a fair condition Royal 880, 3.0 amps, late 1970's at a garage sale today. No bag. Don't know if it is A or B. Hoping B because there is no spring to fasten an A bag onto the tube. Good thing it was only $20. Brush is in good shape. Runs quiet and blows hard. Needs some cleaning. I see a hole for oil. Never had a Royal before. Would I use something like 3 in 1 oil? I clean carpets for a living. My main vacuum is a Koblenz U310 DC, but I really need a powerful and tough bagged vacuum, I'm hoping this might be it. Thanks.