HI FI Stereo 70(also known as Triarama and Stereovision 70) was a 3-D process.(1) Two anamorphic images,one for each eye,were captured side by side on 65mm film.(1) Aspecial lens on a 70mm projector added polarization and merged the two images on the screen.(1) A similar Soviet system known as Stereo 70 did not employ anamorphics,resulting in an aspect ratio of 1.37:1.
This is a few tidbits on 65mm and hope this gives some insight.