>>1434736
I read the first 10 or 20 pages of this. By that time it was very clear that the SIS is the predecessor of the CIA. Probably picked up the name SIS because in 1940 the USA was working very closely with British military and intelligence, so it seemed natural to use the same name as the agency that became MI-6.
I didn't read further into this document, but given that many Nazis ended up in South America from 1945 to 1948, one would expect some discussion of this topic since the SIS focus was on Latin America