My 'Maine' complaint

It's true, rorysa.
The "Heavenly Friend" as you said, had quite a New England accent.

I have never heard that it was to be set in the South. In biographies of R+H they mention that they were put off by the original play's setting (Budapest, Hungary) and only warmed to the idea when somebody put forward the idea of setting it in New England. I always notice New England patterns of speech (ie. the "ayuhs" mentioned above) and in Peyton Place, actors like Lana Turner and Diane Varsi drop their "g's" at times like the characters do in Carousel (ie. in words like 'bustin'). I assumed it was common for local New Englanders to speak in this way.
I agree with 'rorysa' that as good as Frank Sinatra can be, he could not have bested MacRae, who's voice is one of the wonders of Hollywood's golden era. As David Shipman wrote in THE GREAT MOVIE STARS-THE INTERNATIONAL YEARS (1972) : "In CAROUSEL, MacRae proved he could act". Amazingly, he was FOURTH choice when Howard Keel was tied up and Gene Kelly refused to be dubbed. He should have at least been up for a Golden Globe. I wish Fox would release MacRae's last musical film on dvd- THE BEST THINGS IN LIFE ARE FREE. It contains a superb rendition of 'The Birth of The Blues' by MacRae with Jaques d'Amboise performing a sizzling dance routine with Sheree North. MacRae sadly developed gambling and drinking addictions (he was arrested for drunk driving while CAROUSEL was being shot) and suffered a serious stroke in 1982. However he rallied and was described as a "man of prayer" by some newspapers when he passed away in 1985. His daughters are amongst the girls in the fairground sequence. One , Meredith, later starred in Petticoat Junction and died -too young- a few years ago.
I have read that the IF I LOVED YOU sequence was first shot in Boothbay Harbour but the results were too foggy so it was redone back at the studio. A fragment of the earlier version survives in the shot in which Mr Bascombe first appears. The intro to 'When The Children Are Asleep' was also shot on the pier to give Billy time to get back from the beach (though as that-great-sequence was actually shot in Malibu it would have taken him a bit longer...!).They also shot the townsfolk landing on the island, which I'm guessing is why we see a location shot when Billy and Jigger take off during the Treasure Hunt, ie. they would have utilized that area for more than one brief shot.I think only 'Blow High Blow Low' made it to the previews. The cut from Jigger watching Billy's boat depart to the shots of the bay is a bit jarring despite the new underscoring which was no doubt added to "smooth it over". They may have felt the number was too similar to 'June is Bustin' Out All Over', though shots from it feature in all the posters and piano selection albums. As 'You're a Queer One Julie Jordan' comes up so much in the underscoring, it's a pity it was cut. I believe it was a location sequence too.
Unlike most other big musicals of the Wide Screen era, no-one's singing is dubbed. Robert Rounseville and Claramae Turner were both from the Met.I have also read from old film publications that Judy Garland and Jean Simmons were either considered or announced for the role of Julie Jordan. Do the fans know that Barbara Ruick (who died too young of a cerebral hemorrhage while completing Robert Altman's CALIFORNIA SPLIT in 1974,Altman dedicated the film to her and used all the footage of her he had shot) was married to noted arranger and composer John Williams of STAR WARS , LOST IN SPACE and SCHINDLER'S LIST fame?