What is the age of a Glenfield Model 25 serial 69231623?

Starting in 1973, you could subtract the first two numbers of the serial number from 100 and determine the age or year of manufacture.

Before 1973, the first two digits of the serial number, indicated the year of manufacture. So, your model 25, like mine, was made in 1969.

Some online resources point to Brophy as the authority on dating a Marlin/Glenfield. But then Brophy states that the model 25 didn't start being produced until 1977.

i know this to inaccurate as my father purchased the Glenfield model 25 I currently own in 1969, the second year of production which actually stated in 1968.