If it has a sight mounting bulge integral to the barrel a few inches in front of the action... it is a Pre-WWII and could be made as early as about 1936.
If it does not have that barrel configuration, it is likely to be a post WWII. (1945-1964)
Some of the later Pre-Wars had the 3 position safety.
I have a Pre-War built in 1937 which has a
4 digit serial number and does not have the 3 position safety... it is about 85%
Best offer? Anyone?