There does not appear to have been an Original Trilogy box set release on home video before 1995 in Mexico - though if anyone knows differently please post up some images and information - thank you.
1995 - Betamax
An Original Trilogy box set release for Betamax in Mexico…
^ the above images were taken from this online advert for ‘Trilogía La Guerra De Las Galaxias’:-
Although the video below is not a box set release - it does contain relevant info for the 3 OT films being released on Beta in 1995…
‘From the Star Wars Home Video Library #390: 1995 Mexican Beta Original Trilogy’ (with the John Alvin artwork):-
https://www.youtube.com/watch?v=fknIXJjPU1s - a 6 minute video at the Nathan Butler youtube channel.
1995 - VHS