S&W Model 10 German Proof

[manofadventure]

I recently bought a S&W Model 10 .38 Special and I was wondering if anyone could tell me how to tell the age based on the serial number.

the SN is: D59****

If anyone can help me out I would appreciate.

 

[Ron James]

Serial numbers D510001 to Serial number D659901 was used in 1973-1974.