Ahhhh, was going to say the song was very popular in USA immediately after WWII ... but you tipped it of by mentioning Freddy Martin, an American Big Band.
I think it was so popular here because of its ebullience ...It was sung in a sort of mock-Cockney accent...and it seemed to be so typical if the indomitable English spirit when war ended. We used to pile into my uncle's convertable and off we'd go singing at the top of our lungs!
I've gota lov-a-leeeeee bun-chaaaa co-ca-nuts
wow