The chest rig shown below was used briefly, likely between 1981 and 1983 just before the R1 (South African FAL) rifle was replaced by the R4 (South African Galil) (source: correspondance over private message with collector mcoleman762 at iacmc.forumotion.com). It has many features in common with designs produced for the South Africa Police Special Task Force.
This particular chest rig was owned by Tinus De Klerk, former 1 Recce operator and later Lt. Col. Commanding Officer of the Special Forces school in Phalborwa (source: user bousquet123 at iacmc.forumotion.com who I obtained this item from). Another example of this type of R1 chest webbing can be seen here: http://www.newrhodesian.ca/viewtopic.php?p=4624#p4624
Pouches:
Magazine pouches have pull tabs inside. 
Side “grenade pouches” have elastic inside. 
Pouches have drain holes on the bottom.
Holster:
Map Pocket:
Items found inside map pocket.
Large document pocket at back like standard Pattern 83 Chest Rigs.
Shoulder Straps:
Padded shoulder straps.
Buckles:
Buckles are undated.