"Modern Checker" model year visual changes' summary:



1957 - First modern Checker (A8) introduced in December 1956.
1959 - Restyled Checker (A9) with dual headlights.
(1958-1960 - "Armbruster & Company" of Fort Smith Arkansas converted a number of Checkers A8/A9s into 6- and 8-door limousines for export to the Middle East, particularly Turkey).
1960 - Superba (name till 1964) for private owners (A10 code). The switch plastic to metal hood ornament.
1961 - The best equipped Superba Special became Superba Marathon. New redesigned grill end with square front indicators in Marathon only. Marathon also with chrome-plated spear that came from the front fender into the rear door that wasn't found on Superba.
14" wheels instead 15" in sedans.
1962 - A11/A12 instead A10. 6- or 8-door Aerobus wagons' (introduced late 1961) and 4-door 129" wheelbase Town Custom Limousine (A11E) production started. Bumpers with center dips instead straight one.
1963 - Sedans switched back to 15" wheels. New grill with square indicators in other sedans.
1964 - "Superba" name dropped at last.
1967? - Small round retroreflective sidemarkers with clear lenses.
1968 - 1.5" taller front windsheld, bigger back one also.
1969 - Small round sidemarkers with yellow lenses. Last 6-door Aerbous made.
1970 - Bigger round sidemarkers.
1971 - Enlarged front indicators. Separate reversing lights. Rear plate light in tail wall instead mounted in bumper.
1973 - Bumpers with telescopic dampers.
1974 - Huge aluminium bumpers. Last 8-door Aerobus station wagon built.
1975 - "Unleaded Fuel Only" label over filler cap.
1976-1977 - Assembling short series of 8-door Aerobus sedans.
1978 - Paralell wipers instead opposite (introduced in fall of 1977). Interior mirror glued to windshield. Filler cap (mounted on tail wall still) higher and slanted due to safety regulations. Low side strips in Marathon (A12). A bit smaller round sidemarkers probably.
1981 - Two rear plate lights.

* * *
How to distinguish Taxicab and Marathons?

"Taxicab" (A8 / A9 / A11) for fleets.
Less bright on first sight - no side strips, overriders on demand, no wheelcovers or small one, dull aluminium bumpers in 1974+ cars.

"Superba" and "Marathon" (A10/A12) dedicated for private customers.
Richier "jewellery" on first sight - long side chrome strips, "Marathon" side badges, full wheelcovers, overriders and white sidewalls on demand, polished aluminium bumpers in 1974+ cars, more retroreflective elements in tail lights.

* * *
Images get it easy...

Bumpers' shape:
1962-1973 (in 1973 MY bumpers were more protruding)


since 1974


Front indicator:
1961 (in A10 Marathon only), 1962-1970 all cars


since 1971


Front windshield and wipers:

to 1967


1968-1977


1978-1982


Rear windshield. Right one to 1967, left since 1968.


Filler cap:
to 1974 (here 1966)

1975-1977

1978-1982

Many 1978+ cars had black plastic cap instead chrome.

Propane (1982 only) cars


Sidemarker:
to 1966 - none.
1967-1968 retroreflectors:


1969 only


1970-1977


since 1978


Tail light:
1966 Marathon


1975 Taxicab

Tail plate light
to 1970


1971-1979

1980-1982


Various types of lid lock used in 1966-1982 period simulatenously - turning handle with key lock, push-up handle with separate lock, special "bulletproof" lock, or just lonely key lock (most popular).

Tails
1966

1975

1978


Marathon side strips:

to 1977

1978-1982

1978-1982 de Luxe


Perfect original cars' samples with no doubt:

1957 Taxicab


1959 Taxicab


1960 Superba


1962 Marathon


1966 Marathon



1967 Marathon


1968 Marathon




1969 Marathon


1971 Taxicab


1972 Marathon


1975 Taxicab


1980 with optional "Formal Roof"


1981 Marathon


Outstanding Checker history page:
http://www.coachbuilt.com/bui/c/checker/checker.htm

Somebody on another form I belong to recently spotted a Medicar.

https://imgur.com/aPlhjNe