Those vacuums were when design was at its pinnacle. Pleasing to look at and great functionality. "Form follows function". They are similar but still maintain individualistic appearances.
I have the Eureka Challenger and the Kenmore Imperial. I hope to find a nice Singer of that vintage while I'm upright and walking.
I agree with you I think the Singer R3 did it best, but the Eureka model M is a very close second. The model M has become one of my favorite vacs. I'm very happy to add it to my collection.
The beautiful Art Deco styling of the Filtex is timeless. Designed in the late 1930s, the basic design never changed. I love my Filtex, it’s one of the vacuums that stays at home with me.