As I said, as accurate as I can make it, assuming a common centre. My understanding was that Super35 utilized a common top, but was that format even being used in 63? Or were there other formats using a common top in those days? In any event, as Bruce says, either of those framings, ratios, works well, nothing important cut off, nor heads nor chins. I didn't bother with 1.66 lines for that reason.