An archive and google search yielded no results. These words seem straight out of the pages of Archie, or some other 1950’s comic book. I understand the context in which you might use these words, but not how or when they might have originated.
Best guesses:
Kucklehead - a big, dumb guy. One who relies on his knuckles to solve disputes rather than his intellect.
Dreamboat - a handsome and attractive young man, but why the boat reference?
“Knucklehead” I would have thought was a reference to how hard a person’s head was - hard-headed, therefore stupid.
“Dreamboat” - no idea.
Merriam-Webster dates knucklehead from 1942.
The word “knuckle” derives from the Middle High German word “knochel” or “knuchel” which translates into the English word “bone”.
All of this leading to the assumption that knucklehead is merely a variant of “bonehead”.
As to dreamboat;
Boat is not strictly a nautical term. Boat can also refer to a food carrier (as in gravy boat). I would think that dreamboat would refer to the carrier of one’s dreams and not in the sense of an “ideal” boat design.
It has to be earlier than 1942; the Three Stooges used it in the 30s. Partrige quotes from 1944, but that seems late.
Partridge says “dreamboat” dates from the late 50s, and is obsolete. I don’t think is makes any literal sense, but more metaphorically. Or, more likely, someone just started using the word as slang and others liked it.
The Inkspots recorded “Someone’s Rockin’ My Dreamboat” in 1941 (Bugs Bunny sang it a few years later); “dreamboat” in this case seems to mean a vessel.
In 1952 Clifton Webb starred in a movie called “Dreamboat,” in which he played a conservative professor-type whose students discover he was at one time a romantic leading man in the Silents. “Dreamboat” was also the name of one of the fictional silent movies and the coeds started screaming “Dreamboat!” whenever Clifton’s character appeared. Perhaps the movie contributed to the transformation of “dreamboat” from hulk to hunk.
I think Zenster has the correct derivation, bonehead. The 1942 quote was from Life Knucklehead gets his name from an aviation slang word meaning thick-skulled. (This from my Lighter ]
But my Lighter gives 1939 “And you’re just a knuckle-headed farmer girl” from a novel.
Bonehead Lighter gives in a 1908 quote. He gives many a usage of bonehead in print from the teens and twenties. Who knows, maybe the Stooges originated knucklehead?
aseymayo has the first printed usage right. I think that song may have started the term to mean what we think of it today. The song title was in the 1944 Slanguage Dictionary as another fellow is dating my girl. By 1948, Audie Murphy used it in Hell & Back He had a nice old lady and a dreamboat of a sister.
Should anyone wish to listen to the Inkspots sing the song, click here