Is "No Exit" by Sartre in the public Domain?

[Folded Pliers]

I am considering making a video of the play "No Exit" by Jean-Paul Sartre
as translated by Stuart Gilbert.

Does anyone have a way to check if the play is in the public domain
for that translation?

The copyright notice in the books says:
Copyright 1946, 1947 by Stuart Gilbert (he is the translator.)
Copyright 1948, 1949 by Alfred A, Knopf, Inc. (The first US publisher.)
Copyright renewed 1974 by Maris Agnes Mathilde Gilbert (A relative?)
Copyright renewed 1976 by Alfred A Knopf, Inc.

Thank you for any information you can provide.

-Brian.

[Dan S sXe]

According to my copy, it says it's copyrighted by Albert Knopf, and
performance rights should be obtained from
A.A. Knopf
201 East 50th Street
New York, NY 10022

[Graeme Higginson]

Just wanted to take this rare opportunity to thank you both for this almost 30-year-old information (Today is February 2, 2024). I have no idea how content from 1995 wound up on Google Groups and in my search, but it was helpful. Kinda surreal.