Blame the ship logs for this word

In my review of Orwell's Down and Out_, I mention that he devotes a whole section to analyzing swear word, though  "bloody"is the only one that makes it into print in the 1933 book; all the others are just represented by dashes in that wonderfully quaint Victorian device. 

 I'm not sure at exactly what point all that's fit to print allowed for more explicit language to be allowed into books, though I'd venture it was after 1970. Stephen Birmingham seems to get a kick out of including one in acronym form, saying that  "For Unlawful Carnal Knowledge" was recorded in that fashion in ships' logbooks next to records of punishment.  See the footnote on p. 271 of The Grandees.
I did a brief Google search and haven't found anyone who says he is mistaken in the etymology of the word.