Until 1968, only the South African Police, who concluded a secret agreement in July 1962 with the Portuguese government in Tsumeb were allowed to liaise with the Police and Military in Angola.
Going on memory .... The then SAP had several bases in the Caprivi strip along the banks of the Kavango river. Two such were Singelanwe and Chishuma (spelling?) which were both attacked in the late 1960's. Choppers for operational purposes and their crews seldom spent the night at these SAP bases and were mainly based at either Rundu, Katima Mulilo and Mpacha airstrips in the Caprivi. Those who may know which SAAF helicopter units (Alouette 111) participated must now be in their 60's and 70's age wise. Had they still been alive and willing to share their knowledge, the likes of General Hendrik van den Bergh (Lang Hendrik) and Brigadier Theuns Swanepoel (Die Rooi Rus) could provide many answers to these questions. These two police Officers were very involved in much of the fledgling Bush War of the late 1960's. Legend had it that Brig. Swanepoel (at the time a junior Officer) always took a box of hand grenades on the Alouette 111, much to the dismay of the crew, so as to have some aerial bombardment capability!
These news articles, its sources and the outcome, are not freely available. Historians and writers on the War in Angola and especially the operations of the SAAF are also silent about this and the initial deployment of the SADF in Angola almost six years before Ops. Savannah.
Not sure whether the SADF was actually directly involved in Angola in the late 1960's. Possibly covertly.
However, the only man that could and would shed light on this was Colonel Jan Breytenbach - one of the SADF's most inspiring combat commanders and Officers. Bear in mind there was much rivalry between the SADF and the COIN (COunter INsurgency) units of the SAP in those early days of the Bush War, to the extent that Gen. vd Bergh was accused of creating a private army by the SA Army hierarchy. The two forces would not have been happy neighbours in the early days!
The books by Col. Breytenbach 'Forged in Battle' and 'They Live By The Sword' tell of the early liaison and later full co-operation, between the SADF and the Angolans in the mid 1970's, but no mention of anything pre Ops Savannah.
Scope and Huisgenoot magazines had lengthy articles at times on these early days of the Bush War and the Police members involved.
The photo journalist Al J Venter also made various contributions to publications regarding the Bush War.