Horologist to observe manufacturer (10)

I believe the answer is:

watchmaker

'horologist' is the definition.
(I know that horologist can be written as watchmaker)

'observe manufacturer' is the wordplay.
'observe' becomes 'watch' (synonyms).
'manufacturer' becomes 'maker' (synonyms).
'watch'+'maker'='WATCHMAKER'

'to' is the link.

(Another definition for watchmaker that I've seen is " One producing small movements".)

I've seen this clue in The Daily Express.

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