Hi Gary,
I'll see if I can clarify some of your new questions.
1. "So machines made in North America during the 2003-2007 transition period seem to be not purely Electrolux." The orange vacs are all purely Swedish Electrolux. Every design (except the orange Oxygen Three upright) was available to Europeans at the same time - and were most likely designed in Europe and the designs were exported to North America from Europe. They did not originate on the drawing boards of Eureka in Bloomington Illinois. The canisters were all made in the Electrolux plant in Hungary, even though the Oxygen with the power nozzle took on a new power nozzle design and for a while had Eureka attachments. But that's it. I am sure that Electrolux created the orange Oxygen power nozzle vac by shipping 120volt canister units from Hungary to Bloomington, where they were married to a Eureka electrified hose and attachments. These American style attachments were never sold in Europe.
The uprights and power nozzles were probably made in the same Mexican plant as Eureka uprights and power nozzles for economical reasons. But you will rarely see any of these products with the "Eureka" name on them. From 1974 onward, Eureka vacuums (note the name change from "Eureka Williams" to "The Eureka Company") began being influenced by European design and Electrolux corporate decisions, and in fact some Eureka vacs were actually made in Sweden beginning in the 1970's. So Sweden's Electrolux began selling some of their designs in North America under the Eureka and Euroclean names because they were not allowed to sell any vac in North America labelled "Electrolux." Eureka as a purely American company began losing its independent identity back then in the 1980's. No more curvey "e" on their vacs!
2. "I'm confused about when Swedish Electrolux bought back the name. Was it '03? You have the time line of ownership of the name as pre-68, post-67, but you mention them owning it '03-'07. Clarification?" Up to 1968, the Swedes had a minority ownership in the American and Canadian Electrolux plants. They sold that in 1968 to Consolidated Foods. In 1974, they re-entered the North American vac market by buying up Eureka from National Union Electric. In November of 2003, they bought back the rights to use the Electrolux name in North America and the North Americans were left to find a new name to use - they chose Aerus. To give the North Americans time to transition to the new name, they allowed them to use "Electrolux" for an additional 4 years. The Europeans agreed that they would only market a limited number of European Electroluxes in North American stores during that time period, and it was agreed that these would be identifiable by a distinctive burnt orange colour. Once 2007 arrived, the Europeans were free to sell in whatever colour they wanted, and the first change occured when you began seeing those white and green versions of Electrolux vacs at Home Depot and Lowes in Canada.
3. "As to the Electrolux uprights made between '68 and '03, what companies made these?" Not sure if these came off the same assembly lines as the canisters, but these were not made by Sweden's Electrolux. They were definitely marketed by American and Canadian Electrolux companies and sold by their marketing and sales departments and stores. After 1974, Sweden's Electrolux used their Eureka subsidiary facilities in North America to bring in some European vacs under the Dometic name (I think also under the Viking name).
4. "The EL5035 Oxygen 3 is a bit of a monster. Many problems with such seemingly simple things as wheels. Bad consumer rep for reliability; issues with electronics." Which is probably why they were discontinued. BUT: this upright was the top-rated upright in Consumer Reports tests in 2003 or 2004. It was too soon to provide brand reliability details in that report, but it aced all the tests for carpet cleaning, bare floor cleaning, hose airflow for above the floor cleaning, filtration, noise control and ease of use. In fact, I remember that the magazine used a large photo of the vac with labelling to show what features it had to illustrate what consumers should look for in a good upright - including the cord reel.
Hope this helps Gary!
For a nice little summary of the history of Electrolux see this link from Ristenbatt vacuums:
http://www.ristenbatt.com/eu/lux-name.mv?SubWin=Yes