Tom Ridenour himself says that he regrets that he did not maintain control over the production of this instrument. His design was sold to a company in China. He has mentioned, and I have heard it confirmed by others, that many of these instruments have key work that is too soft. There are a few 147s out there which Ridenour himself worked on to bring up to his standards, and they would be fine instruments. These would likely have been bundled with Tom's hard rubber barrel.
One problem is that the painted logo will quickly rub off the clarinet. Recently I was given a no-name Chinese clarinet. It plays wonderfully in tune, and there are a few things that reminded me of the shape of my Ridenour Lyrique's keys. The only problem with it is that the keys are too soft. (The left and right pinkie keys will easily go out of adjustment.) I suspected that this clarinet might be a 147, so I called Tom. He said that all the 147's should play nicely in tune. But after that, he declined to give any characteristics that will set them apart from any other Chinese clarinet. He said that some models were made without the ergonomic register key, and without the sturdy crowfoot or the adjustable thumb rest. He seemed unable to give any characteristic that would indicate his instruments. I suspect, but did not confirm, that all 147s will have separate posts for the trill keys (operated by the right hand on the left-hand joint), like Vitos and most Noblet/Leblanc clarinets.
If buying a used Ridenour 147, I recommend that you only buy if you find one where the owner can show proof that it is really a Ridenour, such as by showing the original sales receipt. Also, I would be sceptical of an unmarked clarinet someone says is a Ridenour if it doesn't have ergonomic shaped register key.
For more information, search for “woodwind.org TR147.”
See my page on Barrels, where I recommend Ridenour's Ivorolon barrel. That barrel will make almost any clarinet sound better!
BUT take a look at the Lyrique 146! It is a professional level instrument at a student clarinet price. See the full review of the 146.