Actors

Bit of a hopeful query for some film experts!

From looking at the IMDB cast lists for this and "War Of The Planets", it seems that a lot of the credits are wrong. For example, Ken is played by the same actor in both, yet is listed as Charles Justin in WWP and Enzo Fiermonte in this one. Freddy Unger's character in this is named in the dialogue as Duvall, but Vittorio Bonos is listed as Duvall.

So my question is: does anybody actually know which characters are played by which actors in these "Gamma 1" films? It doesn't help that a lot of the characters aren't named on screen or in dialogue, and many of the actors aren't listed in the credits. Most of the actors aren't known to me at all. Even Google images struggles to find decent pictures of most of them!

Thanks.