burn it and if its yellow then it is pretty old
With serialnumber 57550 the gun is made ca 1963!!
See link.
By the serial number.
The age of your shotgun is determined by the serial number that was assigned to it.if you wish to include this number in the form of a question we will be able to age your shotgun for you?
That is impossible to determine without knowing the manufacturer and model of the shotgun.
Blue Book of Gun Values
Una Merkel died on January 2, 1986 at the age of 82.
By the serial number
1936
70-100 years.
In order to determine the age of Lefever shotgun, the serial number must be known. However, Lefever shotguns were only made and distributed between 1885-1916.
Merkel has made them since the 1800's