[OSGeo Africa] Kathu coordinate system

[Hanlie Pretorius]

Hi,

I a hand-drawn survey diagram that I need to reproduce in QGIS. The
area is in the Northen Cape, close to the 23° E longitude.

The diagram was done in 1968 and its coordinate system is specified as
'Kathu System'. The y coordinates are given first, are all positive
and they range from about 23 000 to 49 000. The x coordinates are
given second and they range from +31 000 to -153 000.

Can anyone tell me what the specifications for this coordinate system
would be? I.e. the information I would need to create a WKT or proj4
specification for the CRS.

Thanks
Hanlie