This F1 paper car is from metmania. There is another March Ford 761 Formula one car paper model at the site: F1 Paper Models – March Ford 761. This is the second version for this F1 papercraft, another 1977 March Ford 761B here: F1 Paper Models – 1977 March Ford 761B.
You can download this F1 paper craft from here: F1 Paper Models - 1977 March Ford 761B 2th Ver. Free Download [Instruction]