I have now analysed one of the hair samples I received by mail some days ago, and unfortunately Dale Drinnon was right: the hairs in the bag shown on the right of the picture - the rather dark and coarse ones - are indeed from an orangutan. The hairs in the other bag may be an entirely different kettle of fish or primate or something; I have only had one look, and the hairs did not immediately scream "orangutan." But we shall see when I have had a chance to take a closer look.
As for the o.p. hairs formerly discussed in great detail on this blog; I now have the results from one orang expert who has taken a look. This guy, who has been taking care of orangs in one of the biggest zoos in Denmark for almost 30 years, has taken a look at the pictures of the hairs and my drawings:
"In the years I have taken care of orangutans, I have never studied their hairs, so my opinion would probably not be worth much, but for what its worth, I had our vet help me pull some hairs from one of our animals - she didn't like that one bit - and we both had a look through a microscope the way you suggested. As far as we can see, the hairs do not match."