Original Advertisements
Here are posters/catalogs advertising Conn horns in the 1970s, plus some other ephemera.
page from Conn brasswind catalog, 1971-2, courtesy Christine Derksen of the Conn Loyalist - this is an important catalog because it confirms that the YamaConn brass Director cornet is the 19A, copper is 21A, and shows that the 76A was at least marketed in the 1970s
Conn trombone ad, 1973
Conn 16A/B [16H on back] ad, ca. 1974 - while hard to read, it mentions the 16A, 16B, and 16H all had Coprion versions - 18A, 18B, 18H respectively - these late-model Coprion instruments are rare and ones not marked "Director" on the receiver are marked 16A or 16B
Conn 11M/12M baritone saxophone ad, 1977 (we'll count saxophones as brasses in this section)
Conn trombone ad, 1979
Conn Director 18A/B/H brasswind poster, 1980s--note that the cornet and trumpet pictured don't have Amado water-keys
Conn brasswind fingering chart, 1984
Conn International trumpet 201 series flyer, created 2002 by James T. Bachmann, according to the PDF file's history (PDF source)
Conn International 94M soprano saxophone flyer, created 2002 by James T. Bachmann, according to the PDF file's history (PDF source)
Conn "Heritage" 80B/81B poster/ad, 1992