Winchester model 70's were not drilled and tapped for scopes in 1939 (they had no holes in the rear bridge). If your model 70 has a hole in the rear bridge it was done by gunsmith after leaving the factory. Those holes were typically drilled and tapped for a standard model 70 base made after 1946.
Congratulations. How about a picture of your new .358. Include the serial number and we'll tell you what year it was shipped. Maybe someone can offer up a comment or two after seeing pictures.