The DS80, I had one that I used for many years. Kirby's only green model in the small series. I don't remember there being any design difference between the "500" series and the DS80. I think the DS80 was the last of that chassis style before the "classic" series came out, and those things were like trying to vacuum with a Humvee....
Ran across a Celebrity at the thrift about two weeks ago, that one had wheels as I recall. You want I should pick it up for ya?
I had a Constellation 86 as I recall, it was orange. Seen blue ones too from time to time.