There is an interesting article by Ngorongoro on Klickywelt (
here, but you need to be registered on the site to view posts- its free to register however) which describes 5 different versions of the 'early' klickies, depending on the embossing on the feet and the internal skeleton colour. This one looks like Version 3 (internal skeleton the same colour as the torso) or Version 4 (white internal skeleton). Ngorongoro admits the linkage between version numbers and dates of issue is currently unknown, but your friend's figure is probably not from the oldest production runs (and certainly not made in 1974!).
If you are interested in seeing the article, I will ask Ngorongoro if I can reproduce it here on PF (and translate it from the German).