These are old.  probably dried.  looks like a good candidate for moistening with some kind of light oil.  I have done such things by bracing the ribbon in a clamp, then putting the ribbon between 2 sponges moistened with wd-40, then using a power drill to slowly spin the ribbon.  If you over moisten it, then you got to do it again with a dry sponge.  One can also do this with ink too.