Railway employees endorse line in final agreement (9)

I believe the answer is:

signalmen

'railway employees' is the definition.
(signalman is a type of railway employee)

'endorse line in final agreement' is the wordplay.
'endorse' becomes 'sign' (I've seen this in another clue).
'line' becomes 'l' (used when specifying particular lines from a poem).
'in' is an insertion indicator.
'final agreement' becomes 'amen' (eg after a prayer).
'l' placed into 'amen' is 'almen'.
'sign'+'almen'='SIGNALMEN'

I've seen this clue in The Times.

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