I have a Marlin rimfire 22 rifle and I am trying to find out when it was manufactured. The only thing on the barrel is Model 81-DL-22 CAL-S-L-LR-A and Marlin Co New Haven Conn. It has been in my family since about 1950. Does anyone know when it was manufactured? I did contact the Marlin company back in the Spring but no one ever answered.