How old is boosey and hawkes euphonium 650943?

To determine the age of Boosey & Hawkes euphonium 650943, you would need to refer to the specific production records or serial number charts provided by the manufacturer. Boosey & Hawkes has a long history, with instruments made in different decades, so the serial number can provide a clue to its year of manufacture. If you have access to those records, you can find the exact year and thus its age. If not, you might find information from vintage instrument forums or collectors.