Conn 20A Fluegelhorn
Date: 1923, Owned by Clark Mazzio
No, this isn't the wrong picture. This is what is listed as the 20A Fluegelhorn in both catalog "B" (1924) and catalog "C" (1926). I assume that if this had been an error in catalog "B" it would have been caught and corrected in catalog "C". This resembles the later Director models (26A, 14A, 18A, 15A, 17A). Perhaps this instrument was the basis for the Director, who knows. However, unlike the Directors it does have the typical flugelhorn mouthpiece receiver main tuning slide. It must be said that cornets around 1900 often had that as well. Compared to other Conn flugelhorns (both earlier and later ones), this resembles a cornet and my guess would be that it sounded a lot closer to a probably somewhat mellow cornet than what would today be called a typical flugelhorn sound. The extra slides were probably the high/low pitch slides; the 21A is the high pitch version of the 20A.
What Conn said in the 1920's:
Here are two instruments [the other one being an Eb cornet on the same catalog page] very popular in European bands and which are used in the larger symphony orchestras and bands in the United States. The Conn Fluegelhorn is primarily a solo instrument, having a mellow, pleasing voice which lacks the more brilliant tone of the cornet. It is perfectly balanced and of pleasing outline. [....] Both instruments are provided with the new adjustable tension valves found exclusively on Conn products.