I should know this, but I don't. What is a good product to use to really polish an old stainless vac? The crap at the hardware and big box stores doesn't do diddley. I'm not looking for a mirror finish, jusy clean and new looking.
If they're getting over spray from SS bays, start with an aluminium brightener such as Arcadian's nu wall. Do not allow to dry on the surface or it will stain black. Spray on and use a white scotch brite pad (gloved hands of course) to clean. You will not scratch or mar the finish with a white pad.. You can use one grade coarser than the white pad but have to be careful and go with the grain of the metal. Be sure to rinse off before the product dries. It's best to do it at night or first thing in the morning while the vacs are cool to the touch.
They make aerosol stainless polishes but every one I've tried just left a greasy messy finish that will attract dirt.
Believe it or not, one of the best cleaners I've found for stainless is called 'Totally Awesome' from the dollar store and it's cheap. Probably not what you need to restore an old old vacuum but for maintaining its great.