1. What are the model letters for Jeeps?

MA - First Jeep prototype - 1941
MB - Standard military Jeep 1942-1945
CJ-2 - First civilian Jeep model 1944-1945
CJ-2A - Civilian Jeep for production years 1945 - early 1949
CJ-3A - Civilian Jeep 1948-1953 (small measurement changes)
M-38 (or Willys MC) - Military version of the CJ-3A 1950-1955. No tailgate.
CJ-3B - Civilian Jeep 1953-1964. Higher hood for higher F-head engine.
M-606 - Military version of the CJ-3B 1954-1968. Mostly exported for foreign military use.
CJ-4 - 1950 prototype - never produced in the U.S.
CJ-V35U - CJ-3A modified for the U.S. Navy in 1950
VJ - Two wheel drive Jeepster - 1949-1950
M38A1 (or MD) - Military Jeep that led to the CJ-5. 1952-1957.
M-170 (or MDA) - Military Jeep with longer wheelbase for specialized use. 1954-1957
FC-150 - Cab-forward Jeep pickup with 81 inch wheelbase. 1956-1964
FC-170 - Cab-forward Jeep pickup with 103 inch wheelbase. 1957-1964
CJ-5 - Civilian Jeep with 81 inch wheelbase 1954-1971 and 83.5 inch wheelbase 1972-1986
CJ-6 - Civilian Jeep with 101 inch wheelbase. 1956-1975
CJ-7 - 93.5 inch wheelbase. 1976-1986
CJ-8 (Scrambler) - Pickup truck design 103.5 inch wheelbase. 1982-1986
CJ-10 - 119 inch wheelbase. Military and foreign use only.
CJ-10A - Same as CJ-10 except two wheel drive and shorter wheelbase for aircraft manuevering.
C-101 - Jeepster. 1966-1973
M-151 (or MUTT) - Built by Jeep but designed by Ford. Independent suspension. (military utility tactial truck)
M-422/M-422A (or Mighty Mite) - technically AMC, built for Marine Corp use. 1964
M-715 - Truck style 1 1/4 ton. Shared parts with the Gladiator truck. 1967-1969
J - Fullsize pickup truck style Gladiator. 1963-1987
SJ...Wagoneers, Old (Big) Cherokees 1963-1991
VJ...Jeepster 1948-1950
XJ..."Small" Cherokees 1984-2001
MJ...Comanches 1986-1992 (the "M" does not mean military)
YJ...Wrangler 1987-1995
CJ...Pre-Wrangler
DJ...Mostly postal Jeeps with stylings like CJ-3A, CJ-5 and CJ-6
TJ...1997-2003 Wrangler
ZJ...Grand Cherokees 1993-1998
WJ...Grand Cherokee 1999-present
KJ...Jeep Liberty