Actually, Brian Wilson and the Beach Boys would have nothing to do with licensing a kit of this car, unless it was referred to as the "Little Deuce Coupe" ~~~ which would actually be a misnomer. The car depicted on the album cover was not named "Little Deuce Coupe."
It was built and owned by Clarence "Chili" Catallo (the person who autographed Greg Myers' picture). It was photographed by and published in Hot Rod Magazine. In fact, the cover of Hot Rod's July 1961 was a photo of the car with Chili wearing a red jacket and posed over the engine.
When Capitol Records was preparing to release the Little Deuce Coupe album in October 1963, they asked Hot Rod Magazine to provide a suitable picture of a '32 Coupe for the album jacket. Hot Rod selected the Catallo photo from their photo shoot two years earlier, it was used on the album, and the rest is history.
So, licensing would come from the Catallo family (who still owns the car, which has been restored) and Hot Rod Magazine, if the famous photos of Chili and the car were used as box art.
But licensing would not need to involve the Beach Boys. Unless Revell wanted to call it the "Little Deuce Coupe" kit. The name of the song would be licensed by the music publishing company that owns the rights to the song, and probably Capitol Records, as well.
But that would be totally unnecessary. There's not much doubt that a kit would not have to use the "Little Deuce Coupe" reference to sell the beejeezsus out of itself! Just license it from the Catallos and show a blue one on the box. SOLD!
PS: One of the mints did a 1/24 die cast of this car a few years ago. It was drop-dead spectacular!! They referenced it as "The Little Deuce Coupe" and I think they had to pay everybody!