moini.net - Jim Moini's License Plates
OMNIBUS 1939-1960 By 1957, the plates were no longer split up by subtypes.
1939-1956OA 000 or OA 00A
OA 1000 - ??
In "THE BULLETIN ALMANAC AND YEAR BOOK FOR 1941", the prefixes are listed as:

O/A - O/FTaxi
O/H - O/L Livery
O/M - O/X Bus
O/Y - O/Z U-Drive (Rental)

I am not sure when or if this changed before 1960.
I have not seen OY or OZ plates before the 1957 base.

1939 BUSPaul Kovalski
New Jersey Omnibus OM'BS Bus License Plate

1942 BUSfelix2.com
New Jersey Omnibus OM'BS Bus License Plate

1943 BUSfelix2.com
New Jersey Omnibus OM'BS Bus License Plate

1945 TAXIPaul Kovalski
New Jersey Omnibus OM'BS Taxi License Plate

1946 LIVERYPaul Kovalski
New Jersey Omnibus OM'BS Livery License Plate

1947 LIVERYPaul Kovalski
New Jersey Omnibus OM'BS Livery License Plate

1948 LIVERY
New Jersey Omnibus OM'BS Livery License Plate

1948 BUS
New Jersey Omnibus OM'BS Bus License Plate

1949 TAXI
New Jersey Omnibus OM'BS Taxi License Plate

1950 LIVERY
New Jersey Omnibus OM'BS Livery License Plate

1952 LIVERY
New Jersey Omnibus OM'BS Livery License Plate

1955 TAXI
New Jersey Omnibus OM'BS Taxi License Plate

1956 BUS
New Jersey Omnibus OM'BS Bus License Plate

1957 TAXI
New Jersey Omnibus OM'BS Taxi License Plate

1960 BUSPaul Kovalski
New Jersey Omnibus OM'BS Bus License Plate

1957-1960OA 000
OA 0000
It is doubtful if the 1957/58 plates followed the same prefixes as the previous issues.
It seems more likely that they started at some point in the high "O" series (O/Y 100 maybe?) and worked their way up to O/Z 999.

1960Paul Kovalski
New Jersey Omnibus OM'BS License Plate


In late 1959 or early 1960, O/Z 999 was reached, and a new 4-digit series started at O/A 1000.

1959
New Jersey Omnibus OM'BS License Plate

1960
New Jersey Omnibus OM'BS License Plate