GTs58
I'm the Wiz, and nobody beats me!
From that serial number I'm guessing the frame was #49 built in Feb 1949. Pretty dang sure there were no S-5's used during that time.
Did more digging so I'll take yet another stab at the year the raised S-5 came about. In 1959 the Racer and Traveler used the rim PN. 3924 which I believe is the flat S-5. The part number for the rims on bikes starting in 64, or maybe a bit earlier was PN. 3990. Here is the 1962 parts catalog and the 3990 rim is stated as the new style. Raised center?
Did more digging so I'll take yet another stab at the year the raised S-5 came about. In 1959 the Racer and Traveler used the rim PN. 3924 which I believe is the flat S-5. The part number for the rims on bikes starting in 64, or maybe a bit earlier was PN. 3990. Here is the 1962 parts catalog and the 3990 rim is stated as the new style. Raised center?