One gauging strength of, e.g., rum hotel served up with more Cola (13)

I believe the answer is:

alcoholometer

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'one gauging strength of e g rum' is the definition.
The definition suggests a singular noun which matches the answer.

'hotel served up with more cola' is the wordplay.
'served up with' indicates an anagram.
'more'+'cola'='morecola'
'hotel' anagrammed with 'morecola' makes 'ALCOHOLOMETER'.

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I've seen this clue in The Independent.

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