hello the md 58 semi was made from 1956-1963 and to get the exact month and year of production look here and scrool to remington date codes in between the years of manufacture for your date code ,,it will be on the left side of the barrel where it meets the receiver ,,this method should find date of manufacture for most remingtons ,,
https://store.bluebookinc.com/info/PDF/Firearm/
Serialize.pdf
bigcurt