VacLab and HooverLux both have good videos on how to polish Kirby. Keep in mind Kirby uses anodized aircraft aluminum so it might be a bit different than an antique cast aluminum vacuum.If you want to polish a Kirby real well steel wool, mothers mag and aluminium polish and autosol aluminium polish. 0000 steel wool with the Autosol and polish, then 0000 with Mothers Mag And Auminium polish. That came from the Kirby Enthusiast. My little addition is the use microfiber, denim or leather to polish it a bit more with silver/aluminium dip.
There should be a final coat you can put on of a spray on wax or something that creates a protective finish to keep the metal from re-tarnishing so easily.Amazing work. I have a hard enough time keeping a shiny new Avalir 2 shiny much less shining up something to the luster we see that was as dull as it was when you started. Bravo for a great job.