Acronym-etymologies

[Douglas G. Wilson]

There are a number of proposed acronymic word-origins which seem
implausible in varying degrees (to me anyway): FUCK, POSH, PHAT, CHAD,
etc., etc. The bogus retrospective ones are sometimes called 'backronyms'.
But these proposed etymologies are seriously considered only because of the
existence of numerous genuine acronyms: AWOL, NATO, WAC, RADAR, LORAN,
OPEC, etc. It is sometimes asserted that acronyms were infrequent and
[virtually] never served as word origins before the late 19th century.

Recently while examining the possible provenance of the adjective
"hip"/"hep"/"hepped" I ran across a purported early-19th-century-or-earlier
acronym, viz. "HEP" [pronounced "hep"], an anti-Semitic slogan or
rallying-cry, supposedly = "Hierosolyma est perdita" = "Jerusalem is lost".
This appears a transparent backronym: it was apparently most associated
with Germany, and in German sources it often appears as "hepp", which is
also used in German as an interjection to arouse an animal (it seems
similar to the horse-word "hup" in English). Maybe some of the scholars
know better. (Incidentally, it was often reduplicated "hep-hep": is there
any relation to "Hip hip hooray"?)

Anyway, my question is this: can there be backronyms without acronyms?
Although I doubt the Latin sentence was the origin of the cry "Hep[p]!" the
fact that it was seriously suggested as the origin would indicate that
19th-century scholars found the acronym a reasonable way to form words ...
would they have thought this in the absence of any real acronymic
word-origins? (I except acronyms used as imaginary proper names [pen-names
etc.], which seem different to me and I suppose would have seemed different
to the 19th-century folks too.) Or, conversely: if an acronymic word-origin
such as "HEP" was accepted (correctly or not) so early, might not some real
acronyms have been formed ca. 1850 (say) in imitation?

[Note that "acronym" here implies pronunciation according to the spelling;
I am not including initialisms which are pronounced with the letter-names
such as "OK".]

-- Doug Wilson