In other words, are any of the core words in English from the pre-digital era a derivation of other words, abbreviated?
Online I find myself using "wrt" a lot, short for "with respect to". But "wrt" seems short and useful enough to perhaps find itself in use as a conjunction in and of itself (even though phonetically it would sound a bit ugly).
"Lol" has already seen this fate, but that fails to be a pre-digital word. Many pre-digital abbreviations are probably better described as shortenings, rather than concatenations of some other collection of words.