The off-air Beta recordings I've got of ANH from cable back then sport a mono downmix of the Dolby Stereo mix. You'd think it would have been easier for them to use the actual mono track! HBO allegedly used a 16mm print. Some scenes are pan and scanned differently from the video releases and shots like Luke's macrobinocular POV of the lurking Tusken Raiders are squeezed to fit the tv screen.