No 190s sold in North America ever took leaded fuel, and I'd be surprised if Euro versions did either. Model year can be determined from the vehicle identification number (VIN). About the 10th digit of the VIN is a letter corresponding to the model year:

E = 1984
F = 1985
G = 1986
H = 1987
I was not used
J = 1988
K = 1989
L = 1990
M = 1991
N = 1992
O was not used
P = 1993

__________________
1988 California version 260E (W124)
Anthracite Grey/Palomino
Owned since new and still going strong and smooth
MBCA member

Past Mercedes-Benz:
1986 190E Baby Benz
1967 230 Inherited from mom when she downsized
1959 220S Introduced me to the joys of keepin' 'em goin'

There are only 10 kinds of people in the world--those who understand binary and those who don't