Cromwell's great struggle, having no standard parts? (5)

I believe the answer is:

warts

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'cromwell's great' is the definition.
I can't tell whether this defines the answer.

'struggle having no standard parts?' is the wordplay.
'struggle' becomes 'war' (warring is a kind of struggling).
'having no' suggests deleting specific letters.
'standard' becomes 'par' (standard of play in golf).
'parts' with 'par' taken out is 'ts'.
'war'+'ts'='WARTS'

Can you help me to learn more?

(Other definitions for warts that I've seen before include "Skin growths" , "Verrucas" , "feature prominently on 12,14 across [UGLY SISTERS]" , "unwanted lumps" .)

I've seen this clue in the Evening Standard.

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