Dan Wesson manufacture date

[Southern Shooter]

Hello...I have another thread referencing this revolver and its market value...I apologize for double dipping here. But, I am having a tough time figuring out when this revolver was made. It is a Model 15-2 .357 magnum. It was made at the the Monson, MA factory and has the serial number 190xxx. The best that the Dan Wesson people can tell me is the late 70's to early 80's. Does anyone have an idea of its production date?

Thanks