Maybe this should go in the nitpicker's corner, but in my opinion this stuff goes way beyond nitpicking:
I am seriously appalled at the sad state of this site's "episode title origins" page! Following are over a dozen examples of shorts whose name sources have not (until now!) been identified. Among them, I'd say that at least half are particularly notable and are possibly definitive (I've marked these with an asterisk), and the whole shmeer only took me about an hour or two (okay, maybe three...) to research and destroy, so there's no excuse for these not to have been unearthed earlier...
PLANE NUTS (1933) -- "plain nuts!"
ART TROUBLE (1934) -- "heart trouble"
*HORSES' COLLARS (1935) -- No, it's not a clean version of "horses' asses" as the page now ass-erts(!) Actually, "horse scholars" is the title commonly bestowed on top equine experts.
WHOOPS, I'M AN INDIAN (1936) -- The "whoops" part surely refers to an indian's "war whoop".
HOLD THAT GHOST (1941) -- A post can be defined as "a permanent military establishment", so I'm thinking that "hold that post" could possibly been a phrase used throughout WWII with a similar meaning to "hold down the fort".
*NO DOUGH BOYS (1944) -- A "doughboy" is WWI slang for an army infantryman -- the origin of the term is assumed to be in reference to men being covered in flour-like dust after a long march; add to that "no dough", which refers to being flat broke/penniless.
*CRAZY KNIGHTS (1944) -- A probable ref. to the card game "Crazy Eights"; the name of the game dates back to the 1940s and was derived from the military designation for discharge of mentally unstable soldiers, Section 8, hence a "crazy 8".
THE HOT SCOTS (1948) -- Possibly a pun on "hot shots" in part.
WAITING IN THE LURCH (1949) -- Poss. ref. to a bride left at the altar, ie "waiting in the church"?
AIM, FIRE, SCOOT (1952) -- "aim, fire, shoot"
SHOT IN THE FRONTIER (1954) -- Reverse play on "shot in the back".
*STONE AGE ROMEOS (1955) -- "The Fable of a Stone Age Romeo" was a 1923 short from the obscure Aesop's Fable Studio (1920-1929). Not what you'd call a well-known work, but it clearly predates the short.
BLUNDER BOYS (1955) -- "wonder boys"
*BEDLAM IN PARADISE (1955) -- A particularly clever reverse play on "Paradise In Harlem" (1939), a musical comedy-drama biopic about a comedian who witnesses a mob hit.
GYPPED IN THE PENTHOUSE (1955) -- It's a stretch, but there was a 1944 Anne Baxter movie called "Guest In The House". This title (along with "Rumpus In The Harem") is driving me crazy, as it seems that it MUST be some sort of pun -- I'm thinking it may have something to do with "(blank) in the henhouse"?
HUSBANDS BEWARE (1956) -- This may just be one more in a long and varied tradition of "(blank) beware" titles, including Bridegrooms Beware (1913), Bandits Beware (1921), Sailors Beware (1927), Beware of Bachelors (1928), Blondes Beware (1928), Beauties Beware (1929), Buyer Beware (1940), Sailor Beware (1952), et cetera.
GUNS A POPPIN'! (1957)-- "fun's a poppin'"
MUSCLE UP A LITTLE CLOSER (1957) -- From the schmaltzy early 1900s song "Cuddle Up a Little Closer" by Otto Harbach and Karl Hoschna.
Whew! That's enough for one night!
-- mnw