i had a gun of mine looked at years ago and was told it was 1956 5-screw. which would be pre -29 if im correct. recently i did some homework and looked at sn# and found S207xxx. where am i looking to make it a 5 screw. the number i am getting tells me 1960. i thought the 5 screw was only until 56. any help from someone would be appreciated.