Thank you for your replies.
I was unable to fix the problem quickly, so I sub-divided into individual documents.
As it originated from a large historical document, their were numerous styles that weren't used. Even using developer, I could not remove them, as soon as the document was saved and opened again they returned!
I created pdfs and merged into one document which will have to make do.

Note that the styles that are built into Word can't be deleted.

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Stefan Blom
Microsoft Word MVP

Microsoft 365 apps for business
Windows 11 Professional