Re: Conn Bari
First of all, are you quite certain that this horn was made C. 1919? Conn stopped using the double octave key on their horns about half way through the Wonder model's production run, around 1905/1907. Prior to this date, all Wonder, and earlier Worcester models(1888-1895) had the split octave keys.
By 1919, Besides the standardization of the single octave key design, all Conn models were being made with rolled tone holes using the 1914 pat. Haynes rolled tone hole process. Does your horn have this Date stamped on the back of the body near the thumb hook or body/bow ring? Does it have plain metal key touches, or Mother of Pearl (Save for the New Invention models made between 1910 and 1912, Conn used metal key touches until 1919)? Does it read C.G. Conn, or C.G.Conn, LTD? If the former, it was definitely made prior to 1919.
Regarding the double octave key pre 1905 Wonder model horns: This key arrangement is a bit of a nightmare to navigate technically, and makes it more of a minor curiosity among collectors rather than a player's horn. The intonation can be a bit sketchy as well. In addition, these horns feature an awkward neck octave key arrangement on the Baritone, where the key is located on the body bend, and the pip on the neck. This is less of a problem with the fixed neck Wonder models, but became a downright hassle when the New wonder I models were introduced with the same octave key design, but with the neck removable. I'm sure you can see that if the neck is angled in either direction with this arrangement, the key will no longer cover the pip on the neck portion.
Since the later, slightly improved New Wonder series I Baritones can be found for around $1,000 to $1,500 in good working order at present, your horn isn't worth too terribly much in terms of monetary value. The earlier Worcester models can be worth more to Conn collectors (such as myself) because they were the first model Saxophones to be introduced by Conn (and are almost identical to Adolph Sax's original design) but for historical interest only, and for super fine/mint condition specimens. Best of luck.