@centrox,
You says "I would leave an isolated quoted American spelling alone if it swam in a sea of British English."
I am afraid I do not understand your point here. Can you explain it to me, please?
So, can I just use the British spelling from the very beginning?
That is, can I write "Brown (2005: 34) formulates the so-called Generalised Lexicalist Hypothesis." (although he originally uses 'Generalized Lexicalist Hypothesis')?
In my first example (below) there is a direct quotation so I cannot change the spelling.
"According to Plag (2005: 45) 'such atypical behviour is the result of lexicalization.' However, lexicalisation..."