Azimut has long since discontinued their Hogan's Heroes figures, and Jimmy Flintstone makes several of them, but not in 1/35 scale.

I would think that somebody might make heads of these characters, but Hornet doesn't (and won't, presumably for legal reasons), and I don't know of anyone who does. Or does someone do after all? It would be easy enough to stick such heads upon suitable plastic figures; in the actual show, the characters sometimes wore other than their standard outfits.