Acronyms (initial letters strung together and pronounced not as letters but as a word) hardly existed before the Second World War. (The first one appears to be DORA - the British Defense of the Realm Act of 1914).
"SNAFU" dates from 1941.

"Skiboo" is probably just nonsense. Early versions of the "German Officer" song sometimes have "snapoo" instead. More recently there's "Yo ho!" and under the influence of "Mademoiselle from Armentieres," "Hinky dinky parlez-vous."

And at some point, for some singers, the "German Officers" got mixed up with the tune of "When Johnny Comes Marching Home Again."