ANSWER
The stamp, rubber stamp impression on the right top hand side is that of the Commissioner of Police upon receipt of documents, each one is stamped, and it was received on 5 May 1983 in Pretoria.   Then there is a Private Bag No at the top, a reference number, enquiry number Major Ellis, a phone number which is the 017 code, I don't know which area code that is, 4 May 1983, it should be the Welkom because I see the author of the letter is Brigadier JMH Van der Merwe, Divisional Commissioner, Welkom, Brigadier.   It was addressed to the Commissioner of Police with a copy to the District Commandant in Kroonstad which fell under the Divisional Commissioner, Welkom.