Finish with not as much but go on for ever (7)

I believe the answer is:

endless

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'much but go on for ever' is the definition.
I can't tell whether this defines the answer.

'finish with not' is the wordplay.
'finish' becomes 'end' (synonyms).
'with' means one lot of letters go next to another.
'not' becomes 'less' (I've seen this in other clues).
'end'+'less'='ENDLESS'

'as' is the link.

Can you help me to learn more?

(Other definitions for endless that I've seen before include "Sister of Aaron (Exodus)" , "Continual" , "without finishing" , "Everlasting" , "'Eternal, perpetual (7)'" .)

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

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