I could only remember the first half of most of the verses! I don't think I've heard or played this since the 70s. However, these lyrics refresh my memory quite well, so here's a few corrections, informed by the sheet music more than by the diction on the record:

Play One More
(Words and Music by Ian Tyson)

Play one more, and then I'm leavin', boys
Pick one more, let the guitar dream. [ring]
I can't tell you to hold (?), for I do believe
[I can't tarry here too long, for I do believe]
She being high-strung like a swallow on the wing,
She may be gone.

Oh, this smoky, laughing room just seems to ease my mind
Not to mention the few too many that I've had,
So I pack my guitar up, for I do believe,
She being high-strung and lately feeling bad,
She may be gone.

Hmmm, Hmmm, hmmmm.

We ain't been getting' along for a month or more,
Yes, I might be better off if she just goes
But to get home with a dog-tired and empty room
[But to get home with the dawn and find an empty room]
Could I stand the pain, I really don't think so.

So play one more, and then I'm leavin', boys
Pick one more, let the guitar dream (???)
I can't tell you to hold (?), for I do believe
She being high-strung like a swallow on the wing,
She may be gone.
[same as first verse]

Hmmm, Hmmm, hmmmm. Hmmmmm.