i think 1945, per Scott duffs data that you can find on line.
Your M-1 Garand rifle was made by Springfield armory in the year 1955 with the serial number that you provided.
your M1 garand was made in 1940
august 1941
the M1 garand springfield #534068 was made about 1942
rifle made 1942
With the serial number that you supplied,your Springfield M-1 Garand rifle was produced in the year 1943.
According to Fulton Armory and a list of Garand Serial Numbers your Garand was manufactured in April of 1945http://www.fulton-armory.com/tea/m1serial.htm
Your springfield M-1 Garand was made at springfield armory in 1943.
Your Springfield armory made M-1 Garand with a serial number of 5,449,068 was produced in the year 1954.
Your springfield armory made M-1 Garand with serial number 5,843,454 was produced in the year 1955.
Your M-1 Garand was made at Springfield armory in 1955.
Your M-1 garand was made at Springfield armory in 1943.