The Pattern 70 design was based on the British Pattern 58 webbing set. The canvas material is significantly heavier and more durable than the British version. More information can be found here: http://www.nutria.co.za/forum/viewtopic.php?f=48&t=578&p=1766, including the identity of the designer, M. J. Du Toit.
Small Pack:
The 2 large back kidney yokes attached to the waist belt. All other components are removable.
Usage Photos:
Rhodesia and South Africa:
This webbing was mainly used by the SADF in the Border War up until it was replaced by nylon Pattern 83 gear. They are commonly seen in photos from the period. Although contemporary with the Rhodesian Bush War, very few P70 items made it there (source: https://www.newrhodesian.ca/viewtopic.php?p=77528#p77528, https://www.facebook.com/groups/999799990127595/posts/3534599606647608). The few photos showing Pattern 70 items, used by SADF soldiers operating in Rhodesia, are below:
Parabat in southern part of Rhodesia, based in Rutenga (from https://www.facebook.com/photo.php?fbid=4636921159714913&set=p.4636921159714913&type=3). 
SADF Recces operating as Rhodesian SAS D Squadron (from https://www.facebook.com/photo?fbid=10159274214619752&set=gm.3534599606647608)
All Rhodesian usage photos from https://www.facebook.com/groups/999799990127595/posts/3534599606647608.
Call of Duty Black Ops Cold War:
Helen Park’s default skin uses the Pattern 70 kidney pouches. Her belt could be standard British Pattern 58 or South African Pattern 64 like her suspenders.