Found the 1929 lyrics for the Kurt Weill, Bertolt Brecht, Dorothy Lane and Michael Feingold production of "Happy End"
Marianne Faithful changed a few lines, and I left out a couple, but nothing important.
Running through the 1929 lyrics, here are the changes:

And the music really gave you some return on what you paid.
Hey, Joe, play that old song they always played.
That old Bilbao moon
Down where we used to go.
-Who remembers the words?
That old Bilbao moon
-It's just too long ago!
I don't know if it would have brought you joy or grief
etc.

Bill's beer hall in Bilbao, Bilbao, Bilbao,
Came a day at the end of May in ninety-eight
Four guys from Frisco came with bags of
gold dust, gold dust, bags of gold dust,
And the time they showed us all was really great!
But if you had been around etc.

Brandy bottles smashing everywhere

'N those four guys from Frisco all went crazy with their pistols blazing high
Think you can stop them? Well go ahead and try.

That old Bilbao moon
Down where we used to go
Can't remember the words
That old Bilbao moon
-Something with love in it
I don't know etc.

With potted palms and ice cream etc.

Well if you should come around to see the fun
Well, I don't know, you might not find it such a pain (Huh!)

They've mopped up all the booze and broken glass
etc.

(Stage direction- Bill shouts the lyrics between phrases, and OTHERS pick them up and sing them. It's obvious that he's the only one who knows the song)
Everybody-
That old Bilbao moon
Down where we used to go
etc.

It was fantastic
Beyond belief.
(Bill, spoken) And it's all over now.
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I will put the stage version together later, now that I can compare the two. Interesting comparison.
Faithful did a good job of taking a song sung on stage by more than one person (Governor, Baby Face, Bill Cracker and The Gang).

Faithfull changed the 'guys from Frisco with bags of gold dust' to 'guys from Bristol with bags of coal dust'; I guess for her mainly UK audience, but it doesn't really make sense.

Script found on google-
Happy End: A Melodrama with Songs- Google Books Result. I am no good at cut and paste, so won't try a direct link.
The book was published by French's Musical Library.