One working with Scotsmen and old Greeks (7)

I believe the answer is:

ionians

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'old greeks' is the definition.
'Ionians' can be an answer for 'greeks' (Ionian is an example). I am unsure of the 'old' bit.

'one working with scotsmen' is the wordplay.
'one' becomes 'i' (Roman numeral).
'working' becomes 'on' (e.g. a machine is working or on).
'with' says to put letters next to each other.
'scotsmen' becomes 'ians' (I can't explain this - if you can you should give a lot more credence to this answer).
'i'+'on'+'ians'='IONIANS'

'and' acts as a link.

Can you help me to learn more?

I've seen this clue in The Independent.

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