I can't relate to soaring in the 50's or 60's in Southern Africa , but
flew a number of "Rhodesian nationals" in the 70's . These took place
out of Warren Hills near Salisbury and conditions were often very good
with many 300-500km tasks set . Alf Thompson was the contest director
and had a reputation for tough tasks. I now live and soar out of
Indianapolis ,IN and know a number of ex Rhodesian pilots and others
who flew the Rhodesian contests fly out of the Magaliesburg club in
South Africa- you might try thier excellent website .