The topic has been discussed several times here in C&V. Not sure I can shed any more light on it than what's above.

I can address the items in your first-hand comparison, as I have both a 56cm Cinelli Equipe Centurion and a 56cm Cinelli Super Corsa.

First, the actual name. It was called the Cinelli Equipe Centurion, which I believe means Cinelli "Team?" Centurion.
That could be interpreted to mean that some Cinelli entity made the bike for Centurion as a "team" bike. The "team bike" marketing approach, if you recall, was used a bit back then, but the ones I'm most aware of being marketed that way were later 80's Japanese-made bike.

Now, the comparisons you list are correct. It's definitely not a Super Corsa. I do not know of other models made by Cinelli, the firm that was making the Super Corsa at the time. I'd like to see the frame weights, though, as my Equipe frame is nearly identical to my Super Corsa frame in weight, if not lighter. They ride identically. I truly cannot tell the difference in ride, in any way, shape, or form, and that's with similar wheels and groups.

There have been other examples of the Equipe that looked like yours, that is, with the turned seat stay logo and the internally lugged fork crown vs. the externally lugged fork crown. afilado here has one very much like yours in blue. ggl205 has another, with some other slight differences, and there definitely was a black model out there with some of the same subtle differences. It's entirely possible that the Equipe, which came from a shop in Italy somewhere, under the design and supervision of Cino Cinelli, was made in several slightly different versions. It was a very limited production "run" from a smaller shop, and it's easy to see how some differences would be possible. poprad, jan nikolajsen, A.Winthrop, and valentinodel also have versions of the Equipe, or had them.

A seller in Maryland called 123bikes.com had several for sale, and it appears the site is down.

My best educated guess is that your red frame is more likely to be an Equipe than anything else I know of. I have a head tube badge that you may be interested in, incorporating Centurion with the Equipe logo. In my experience, most of the Equipe owners tend to want to remove the Centurion branding from the bike.

The only thing "Centurion" about the Equipe were the DT and HT decals. These, as far as I know, were produced in lavendar/black, orange/green, and red. The red set had the word "project" in the HT decal.

That's a beautiful bike, looks like a powder-coat, and you've got it set up very nicely. Excellent work.

The eBay example is very likely one of the Equipes, and the decals, I think, are by CyclArt.

http://velospace.org/node/25487

http://velospace.org/node/41422