I'm no expert on Araucanas, but I can say that if it is rumpless, it most likely has significant Araucana in it or is an Araucana (rumpless is dominant if I remember correctly, but with the genetics of the 2 genes, Araucana would have to be fairly close back).
I think there are only 5 accepted colors in the US: black, white, black breasted red, silver duck wing, and golden duck wing. The UK has a lot of colors accepted, plus European Araucanas have tails, beards, and ear tufts...the difference in philosophy of breed development between the UK and US.
Your bird looks blue to me, but that doesn't mean it isn't an Araucana, just not "show worthy" as it would not be one of the accepted colors in the US, but would be in the UK (where blue and lavendar are accepted). Many US Ameraucana and Araucana breeders like to work on the blue and lavendar colors even though they are not currently accepted (with hopes to make them accepted in time).
It also does not appear to have ear tufts, another disqualification for the show ring, but allows for breeding (2 tufted birds bred will produce at least 25% chick fatality as 2 tuft genes are fatal, so breeders breed a tufted bird to a clean faced bird to produce chicks with tufts that live, sacrificing that there will be a good percentage that will have no tufts).
As to the no-crow collar. I've not yet tried one...yet... but have been tempted. (I even own one). While roosters are legal where I live, I am keen to keep happy neighbors, so if my rooster is too noisy, I am prepared to put a collar on it if it is a bird I want to keep. Thus far my Barnevelder roo has been a polite boy, so I haven't had to resort to it yet, as my closest neighbors like the sound of the occasional crow. But he's still younger, and as he "man's up," he may see the use of the collar if he becomes too vocal.
I purchased mine from My Pet Chicken. It seems well made, but is completely over-priced. You truly could make something like it yourself with 1/8 inch self stick velcro strips and some mesh. I bought an offical No Crow collar so that I could have a pattern should I find I need to resort to it as I've read they don't last long, depending upon bird and wear and tear. There are some BYC articles on self-made ones.
I do know, from reviews on the collar, that you have to be careful and watch your roo to make sure it is fitting properly. An improperly fitted collar either will not work or can choke the bird (to death by some reports). But, for many it is worth the effort as the roo would have to be given away, and generally to the soup pot, unless the crowing can be stopped or limited. From reports the collar appears to work on a number of birds, with overall happy customers plentiful enough that it appears to be a good idea. From the reviews I've read, failure seems to be likely from improperly placed collars and over tightening.