1. Boosey and Hawkes is a combination of the Boosey company and the Hawkes company. Hawkes produced their own instruments, for a time, and combined with Boosey in the 1930s. Boosey and Hawkes have been, since that time, sheet music producers and importers.
2. A lot of the saxophones stamped "Boosey and Hawkes" are stencil instruments. To read more about stencils, please read my article HERE.
Horns stamped "The Buescher Band Instrument Company" from the 1920's are stencils, as are the modern BU-series of horns available from Selmer, and follow different serial number charts.
1. A small, but significant, percentage of all Buffet and/or Evette-Schaeffer woodwinds in the 1900-1930 range (or so) were Conn stencils and do not have Buffet serial numbers. In the 1990's, Keilwerth stenciled a saxophone for Buffet called the "Expression" and that model has a Keilwerth serial number.
2. The modern Buffet 400 (and similar) are Asian-made and do not follow these serial number charts.
1. The Bundy in question here is from approximately 1950 to date. Earlier horns were a mixture of Conn and Buescher stencils.
2. For a brief time, Bundy and Bundy Special saxophones were available from Keilwerth and Dörfler & Jörka, are stamped "Made in Germany" and do not have a Bundy serial number.
Except for the ST-90 I and EX-90 I and II, the ST-90 and EX-90 were not made by Keilwerth and probably do not have Keilwerth serial numbers. For a chart of those models, see THIS.
The modern Kohlert instruments are made in China or Taiwan. Their serial number format is completely different. The serial numbers listed here are for the German/Czech made instruments.
Leblanc does not give out serial number charts. If you ask them, EXCESSIVELY NICELY, about a serial number off a horn you own, they might tell you when it was made.
Vito saxophones have been made by Vito (Wisconsin), Beaugnier, Leblanc, Yamaha, Jupiter and Yanagisawa. Keep this in mind when attempting to date your instrument.