It has a wonderful score (and the OCR is pure delight) but ....
It is the wrong score to tell that dark, tragic story.
When you listen to it it conjures images of fun, frivolity and lavish production numbers. But that is not what the story is about. She wants him to love her...and he can't. (Interestingly, B.Peters did the same basic story 10 years later in SUNDAY IN THE PARK. In that case the score and story fit together.)
Though the lighter numbers can be used as ironic counterpoint (most effective in "Tap Your Troubles Away") but most of the time the songs don't advance the plot or develop characters. I would suggest keeping: "Movies Were Movies", "I Won't Send Roses", "Wherever He Ain't", "Time Heals Everything", "Tap Your Troubles Away" and "I Promise You a Happy Ending." The other songs - as wonderful as they are as songs - don't work and need to be replaced. And the book needs to develop the story so that we care more about Mack and Mabel.
Cast albums are NOT "soundtracks."
Live theatre does not use a "soundtrack." If it did, it wouldn't be live theatre!
I host a weekly one-hour radio program featuring cast album selections as well as songs by cabaret, jazz and theatre artists. The program, FRONT ROW CENTRE is heard Sundays 9 to 10 am and also Saturdays from 8 to 9 am (eastern times) on www.proudfm.com