Self-government advocate finds quarters for king (4-5)

I believe the answer is:

home-ruler

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'self-government advocate' is the definition.
The definition suggests a singular noun which matches the answer.

'finds quarters for king' is the wordplay.
'finds quarters' becomes 'homerule' (I can't explain this - if you can you should believe this answer much more).
'for' says to put letters next to each other.
'king' becomes 'R' (abbreviation of Latin rex).
'homerule'+'r'='HOME-RULER'

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

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