Headlight codes

15N
The last of the code visible is 15 N. The number 15 is the weeknumber the headlight was produced in and the letter N is the year 1955.
Below there’s a list of letters and years.

Hella
K = 1952
L = 1953
M = 1954
N = 1955
P = 1956
S = 1957
T = 1958
U = 1959
V = 1960
W = 1961
X = 1962
Z = 1963
A = 1964
B = 1965
C = 1966
D = 1967
Bosch
(Start at A in 1945)
E = 1949
F = 1950
G = 1951
H = 1952
J = 1953
K = 1954
L = 1955
M = 1956
N = 1957
P = 1958
Q = 1959
R = 1960
S = 1961
T = 1962
U = 1963
(3-digit numbering system starts in 1964)