This is somewhat related to the discussion of classical auxiliary verb ふ, mentioned in the answer to snailboat's question, What is the わ in 忌まわしい and 嘆かわしい?. Another apparent iterative / repetitive ...
I'm looking at this picture of the 日米和親条約 (Kanagawa convention) from the late Edo period and it seems rather strange: It looks like the non-kanji parts are rather haphazardly written in katakana ...
If I look in Google Ngrams, I see that the transliteration "honbu", meaning HQ, basically didn't exist until 1964. But it didn't surpass "hombu" until 1976. I believe Modified Hepburn was introduced ...