Bonjour !
Au vu de la dernière photo postée du caillou, le numéro permettant de connaitre l'année et le lieu de fabrication est UC0502 ce qui donne : fabriqué à Utsunomiya, Japan en mai 1988.
"Canon has been stamping date codes on cameras and lenses since about 1960.
The first letter, "U," means Canon's 3,000 employee, 750,000 sf (75,000 m^2) lens plant in Utsunomiya, Japan, founded in 1977.
"F" would mean Canon's 1,200 employee, 1,300,000 sf (125,000 m^2) Fukushima plant founded in 1970.
"O" will mean Canon's new (production starting May 2007) Oita lens plant with 600 people and 160,000 sf (15,000 m^2), and so on.
Canon uses the second letter for the year. Canon started with A in 1960 and made it to Z by 1985.
In 1986 they started again at A and today, in 2007, have made it back up to V.
The next two digits are the month.
No one has decoded the last two digits.
Early date codes may have had the first letter (the factory code) on the end, so the first letter would be the year.
Canon Year Codes
A 1986 1960 2012
B 1987 1961 2013
C 1988 1962 2014
D 1989 1963 2015
E 1990 1964 2016
F 1991 1965 2017
G 1992 1966 2018
H 1993 1967 2019
I 1994 1968 2020
J 1995 1969 2021
K 1996 1970 2022
L 1997 1971 2023
M 1998 1972 2024
N 1999 1973 2025
O 2000 1974 2026
P 2001 1975 2027
Q 2002 1976 2028
R 2003 1977 2029
S 2004 1978 2030
T 2005 1979 2031
U 2006 1980 2032
V 2007 1981 2033
W 2008 1982 2034
X 2009 1983 2035
Y 2010 1984 2036
Z 2011 1985 2037
"