It is a Getzen serial number.
1968-1971
A Selmer trumpet with a serial number of 43417 was made in 1950, so as of 2013 it is 63 years old. All Selmer trumpets have a serial number and there is a chart that shows what year the trumpet was made.
You forgot the serial number.
It depends on the serial number.
That would be the serial number which can be used to date the instrument. Your Boosey and Hawkes trumpet was made around 1964 according to that serial number.
1968-1971
Impossible to say without the serial number
A Selmer trumpet with a serial number of 43417 was made in 1950, so as of 2013 it is 63 years old. All Selmer trumpets have a serial number and there is a chart that shows what year the trumpet was made.
You forgot the serial number.
A serial number is meaningless without knowing the manufacturer.
It depends on the serial number.
A serial number without a brand is meaningless.
Serial number
That would be the serial number which can be used to date the instrument. Your Boosey and Hawkes trumpet was made around 1964 according to that serial number.
Best estimates put this trumpet as being manufactured after 1984.
A serial number is needed to determine the age of a Bach Stradivarius trumpet.
1952