these were probably done with a 3 colour process that dates back almost as far as the beginning of the century.
Ive doctored some of them as there seemed to be quite a bit of red shift in a lot of the pictures. Anyway if you are interested heres a few with the originals to compare:
original
doctored
by the way what are those 2 guys in grey at the back wearing? Are they Hitlers personal coasters?