A fantastic car ahead of its time from which not only the CanAm versions were derivated, but also the very successful 956s and 962s. It is also a very tiny car, proper 1970s look with a lot of curves rather than sharp edges. Fat rear tyres and powerful engine made this car quite challenging to drive at high speed, hence why 2 versions existed, the K for "Kurz" and L for "Lang", as Porsche did with the 956.
The CanAm version is somehow special in the sense that Porsche arrived in America against teams and cars that were here from a longer time, mostly with V8 engines, while they came with a turbocharged engine, which soon became much more powerful than the others, eventually killing the competition.
The last picture you posted with the white 917s were for the FIA inspection in March 1969 (wow, 45 years ago!).