Where these are of interest and, indeed, come into their own, is for the player on a budget! The internet and Craigslist abound with old wood clarinets of low price and unknown provenance and many of them, after restoration, are good to excellent players.
Some are brands lesser known in America, like Couesnon, Malerne, Moennig or Rampone - good players all, when properly restored. Others are the true stencils, many made by the same companies or even by Buffet, Selmer, or lesser known workshops of high quality (like Thibouville Freres).
Some can be identified by comparison with keywork: Buffet and Thibouville in particular have easily identifiable keywork, if you know where to look. Some can't be identified at all (like the aforementioned Nameless Albert system) but are fine players nonetheless, especially if they have pro features like extra keywork, post lock-downs, metal lined tenons, solid alloy keys, and leaf springs.
Generally, they can be purchased for $25-85 and overhauled for $250-350. A good playing, wood clarinet for a final price of $425 or so tops? Yes, Virginia, there is a Santa Claus! I've restored dozens of these for satisfied customers and purchasers worldwide, and there are lots more out there. Go find one and spend the other two grand on something useful!