CAI stands for Century Arms Incorporated (or International, I forget which). This is just the name of the company that imported (not built) the firearm.
Why it is called a Model 70, I have no idea. Perhaps someone copied the Winchester Model 70 action in Russian or other European factories, and sent them over here. I would imagine that the patent on the original Winchester Model 70 action has long expired and is free to copy.
Regards,
Mannyrock