Date Code

K 1968
Z 1969
M 1970
X 1971
B 1972
L 1973 (1987)
O 1974
S 1975
R 1976
A 1977
U 1978
F 1979
E 1980
G 1981
I  1982
C 1983
H 1984
T 1985
P 1986
L 1987 (1973)
Y 1988
N 1989
D 1990

Size chart

cm -------Uk------- US

54 -- 6 5/8 -- 6 3/4

55 -- 6 3/4 -- 6 7/8

56 -- 6 7/8 --    7

57 --     7    -- 7 1/8

58 -- 7 1/8 -- 7 1/4

59 -- 7 1/4 -- 7 3/8

60 -- 7 3/8 -- 7 1/2

Ministerium des Innern.
Feuerwehr-Fire Police.
General, gabardine fabric, one piece cockade and yellow cap cord , purple piping, purple band, two grommets/vent holes on each side of crown. Size 58 and dated "D" (1990). Black band. (Visor type S3117/3i, o-r). VEB 1856.
Lieutenant to Colonel, gabardine fabric, single piece cockade and silver cap cord, purple piping, two grommets/vent holes on each side of crown. Size 57 and dated "D" (1990). Black band. (Visor type S3117/3i, o-r).VEB 1856.
Side cap. Gabardine fabric, circular textile cockade, purple piping. Size 55, date not readable. VEB 1856.
Freiwillige Feuerwehr-Volunteer Fire.
The cockade and sweat sheild are missing. I replaced the cockade for this photo. Gabardine fabric and black cap cord, vulcan fiber visor, purple piping. Size is about 56? The hat dates from before 1961/62, the cockade is the type used from the early '60s. Brown band. (Visor type "pre-65"). 
Skimuetze. Older style "Bullseye" cockade. Size ?, date ? Made by Roland Mutze. Date before 1963?
Female cap/kappe. Embroidered cockade. Size  53, no date, no markings.
Gabardine fabric, circular textile cockade, Metallic Silver piping. Size 54, date "Y" 1988. VEB 1856. Zoller page 121, abb. 89 a.