I would say that with the serial number 1321XX,we are looking at your shotgun being made by ithaca(who made the lefever nitro special) in 1924.
The Ithaca Gun Company acquired Lefever Arms in 1916, and manufactured the Lefever Nitro Special between 1921 and 1947. The serial number on your gun indicates it is an "A Grade" made in 1937.
1929
Made in 1925
CHeck the receiver and under the forearm
Ithaca Firearms manufactured the Lefever Nitro Special after it purchased Lefever Arms Co. in 1916. This model was made between 1921 and 1947; the serial number indicates yours was made in 1929.
The Lefever Nitro Special was made by Ithaca. Yours was made in 1923.
The best that I can say is that the Lefever Nitro special was made from 1921-1948.I do not know if the serial numbers to year of production is available in the public domain.
Ithaca Firearms manufactured the Lefever Nitro Special shotgun with serial numbers between 101600 and 119899 in 1922.
Ithaca Guns manufactured the Lefever Nitro Special after it acquired Lefever Arms in 1916. This model was made between 1921 and 1947; the serial number indicates yours was made in 1924.
Made in 1925
That Lefever was made in 1923.
1927