South African Airways operated 8 different DC-4 aircrafts between 1946 and 1967.
Registrations used were:

Type Douglas C-54A-10-DC

ZS-BWN "Swartberg"

Type Douglas C-54A-15-DC Skymaster

ZS-BYA

Type Douglas DC-4-1009

ZS-AUA "Tafelberg"
ZS-AUB "Outeniqua"
ZS-AUC "Drakensberg"
ZS-BMF "Amatola"
ZS-BMG "Magaliesberg"
ZS-BMH "Lebombo"

In the collection 1 of the 8 aircrafts is depicted.

ZS-AUB
Construction number 42934, model Douglas DC-4-1009.
Delivered in May 10 1946 named Outeniqua.
In service until September 1967. To South African Air Force, registration 6905.
ZS-AUB was the last DC-4 in SAA service.

Interior views

South African Airways operated 4 different DC-7 aircrafts between 1956 and 1967.
Registrations used were:

Type Douglas DC-7B

ZS-DKD "Drommedaris"
ZS-DKE "Reiger"
ZS-DKF "Goede Hoop"
ZS-DKG "Chapman"

In the collection 1 of the 4 aircrafts is depicted.

ZS-DKE
Construction number 44911, model Douglas DC-7B.
Delivered in March 1956 named Reiger.
In service until 1967. Sold to Boreas Corp., registration N-1760.

South African Airways operated 4 different Constellation L-749 aircrafts between 1950 and 1962.
Registrations used were:

ZS-DBR "Cape Town"
ZS-DBS "Johannesburg"
ZS-DBT "Pretoria"
ZS-DBU "Durban".

In the collection 1 of the 4 aircrafts is depicted.

ZS-DBS
Construction number 2630, model Lockheed Constellation L-749A.
Delivered in 1950 named Johannesburg.
In service until ???. Sold to Trek Airways, registration renamed the same.

Unknown registrations

South African Airways operated 10 different Boeing 707 aircrafts between 1960 and 1980.
Registrations used were:

ZS-SAA "Johannesburg" (ex ZS-CKC)
ZS-SAB "Cape Town/Kaapstad" (ex ZS-CKD)
ZC-SAC "City of Durban" (ex ZS-CKE)
ZS-SAD "Bloemfontein" (ex ZS-DYL)
ZS-SAE "Windhoek" (ex ZS-EKV)
ZS-EUW "Pretoria"
ZS-SAF "Port Elizabeth" (ex ZS-EUX)
ZS-SAG "Durban" (ex ZS-FKT)
ZS-SAH "Pretoria" (ex ZS-FKG)
ZS-SAI "East London/Oos Londen"

In the collection 1 of the 10 aircrafts is depicted.

ZS-SAD
Construction number 18891, model Boeing 707-344B.
Delivered August 27 1965 named Bloemfontein.
In service until 1980.
After September 1980 the aircraft was leased to a number of different operators.
If SAA still owned it or not is not clear for me.

Unknown registrations

South African Airways operated 9 different Boeing 727 aircrafts between 1965 and 1982.
Registrations used were:

ZS-SBA "Tugela" (ex ZS-DYM)
ZS-SBB "Limpopo" (ex ZS-DYN)
ZC-SBC "Vaal" (ex ZS-DYO)
ZS-SBD "Oranje/Orange" (ex ZS-DYP)
ZS-SBE "Letaba" (ex ZS-DYR)
ZS-SBF "Komati" (ex ZS-EKW)
ZS-SBG "Swakop" (ex ZS-EKX)
ZS-SBH "Marico"
ZS-SBI "Kei"

In the collection 2 of the 9 aircrafts is depicted.

ZS-DYN
Construction number 18893, model Boeing 727-044.
Delivered July 8 1965 named Limpopo.
In service until 1982.
In September 1982 sold to Pan Aviation, registration N722GS.

ZS-DYP
Construction number 18895, model Boeing 727-044.
Delivered August 23 1965 named Oranje/Orange.
In service until 1981.
In December 1981 sold to Liberia World Airlines, registration EL-AIZ.