I wonder if the original 1967 cut still survives? Was it ever screened in public?
Yes it does! It runs 68 minutes long. Basically, to shorten the 1967 huis-clos to 55 minutes in the 1981 version, JS didn't delete any complete scene (except an incredibly bitter dialog ending scene between JS ans Joanna Sczerbic), but cut little fragments all along the way.
I must admit i do prefer the 1967 version because the allegory of the 1981 prologue is somewhat too obvious. The 1967 and 1981 are alternatively screened regularly on polish TV. The 1967 version is rarely (but sometimes) screened in international retrospectives