If it is of any help. I just finished five rolls of the Konica 750. I rated it at EI3 with the 89b filter, and bracketed one below and above. D76 1+1 at 70 for 11m.
I have not contacted everything yet, but generally the frames with additional exposure were closer to the mark. Of course everything has to do with the quality of the light, but it appears that EI3 is a good starting point. You will get workable negatives.
I do not know about the other films you mentioned.