>U-10-S (I believe).
Probably U-10-5
The 5 is the last digit of the year..(The U is the month)
We need to guess the decade, it's not part of the date code,
Bet'r Grip starts in 1933.
Broached hang hole runs 1930's to 1947
Unfortunatly, that leaves the decade ambiguous, so either 1935, or 1945....
The typeface would probably lean toward the later date tho...