The AMC is made by the Electric Vacuum Cleaner Co, being a private label for the American Marketing Corp. Their primary brand was Premier(like the Duplex shown later), followed by the GE branded machines. The GE version was model 111, and the Premier version was known as the "Grand".
The Dayton is incredibly rare, and appears to be made by Doty, which mainly made a red non electric push vacuum under the Doty name. That Dayton is likely the only one left in the world(if someone knows of another one, prove me wrong!)
That Clock vacuum is amazing, I've never even seen one. Is it electric or??
The Duplex was made around 1926. 1915 is the patent date for the general design, as they made several straight suction uprights after 1915.
That Tri Point, I have no idea. At first I thought it was a European floor buffer, lol.
The W~E Sturtevant! The motor was made by Western Electric and everything else was done by the Sturtevant Blower Company. They made them in sizes up to the average current shop vac.
The Richmond; Tom Gasko(Dysonman1 here) has one. I heard it was made around 1910 or 11, and had an optional set of wheels behind the head. It also depicts an attachment set in one of the ads.
The Nilfisk is certainly not from the US, they were sold everywhere in Europe however. Thats about all I know on it.
I saw a canister from Europe that reminds me of the cannon, but the cannon appears to be an upright so I am clueless.
Value for an old vacuum is how badly someone wants it. A good comparison that comes to mind is that nowadays more people nowadays want a 69 Dodge Charger than a 1910 Stanley Steamer. The same goes for vacuums. They are worth a fair amount of money to me anyways.
An ad for the Vital:
https://www.atticpaper.com/proddetail.php?prod=1917-vital-automatic-vacuum-cleaner-ad
A vid of the Premier Grand(the AMC rebadge)
Ad for the Duplex:
https://www.ebay.com/itm/192447220064
Doty non electric, their main vacuum related endeavor:
https://www.worthpoint.com/worthopedia/antique-1910-doty-vacuum-sweeper-440941802
Richmond ad:
https://www.ebay.com/itm/393531790434
Western Electric Sturtevant ad:
https://www.ebay.com/itm/294419378691?hash=item448cc33203:g:IQoAAOSwNiBhT3U8
As for the Sanitator, I know of 1 maybe 2 collectors that have one, and I cannot find any ads for that model.
Anyone with additional info, please chime in.