Hi all. I just discovered this thread tonight, so I haven't gotten a chance to read all the way through it. I just ordered my first Araucana hatching eggs today, so I'm eagerly awaiting their arrival and reading up in the meantime.
When I was in college, we had a field station with all kinds of animals, and I spent my time there working with what we called rumpless chickens. They were bantams (or very small standards), all the colors of the rainbow, and laid colored eggs. They had beards and muffs, but I never saw an ear tuft. Their rumpless trait worked the same way the tufted gene does--dominant and lethal in the homozygous state. Does anyone here know what breed these chickens were? And is the Araucana rumpless trait from a different gene? Thanks!

The only other breed I can think of that's close to your description is ameraucana. They have the beards and muffs, and lay blue eggs, but they have normal tails.
I think cashdl mentioned earlier that the araucana breed was standardized in the 70's or thereabouts? Maybe the chickens you worked with were nonstandard araucanas.