A thru N =1949 thru 1962 P = 1963 R thru V = 1964 thru 1968
The stevens model 9478 shotgun was made between 1978-1985.
Most all Stevens 9478 models were made between 1978-1985
Dating a Stevens 12 gauge model number g20a and serial 12202 is best done by the name on the gun. Where only Stevens appears the gun is likely made between 1940-1991.
try the barrel or receiver.
Your stevens model 9478 was made by savage/stevens between the years 1978-1985.
The Stevens Savage Model 124 12 gauge shotgun was made from 1949 to 1954. The serial number will signify the actual year of manufacture.
If it was manufactured before 1968 it probably doesn't have one.
4
No way of knowing without a serial number /model number to identify what type of .410 gauge stevens you have.
The exact value of a Stevens 12 gauge model g20a is actually dependent on a couple things. Some of these things would be the age and condition.
model 77 does not have a serial number,they were made before serial numbers were required
If it is side-by-side, probably Stevens.