There is no widescreen Laserdisc release with the original 35mm stereo mix from 77. Not in the US and not in Japan at least. I cannot speak for other countries. Also all widescreen tapes in the US are the 1985 mix or 1993 mix.
The original mix is on the first issued pan and scan time compressed laserdisc in Analog sound, and on the 1985 CAV release. It is on the Fox rental tape VHS and the first issue non rental tape.
It also is in digital format on a pan and scan Japanese Laserdisc.