As I see it I have two options, fistly amend the exisiting successful campaign hoping that I will benefit from its long successful 'on topic' history. Or secondly create a brand new campaign and hope that my 'on topic' history at account level is strong enough to kick start the new campaign.
Any thoughts or advice gratefully received.
If you might need it again, then make a new one.
History settings, success settings, etc are based both on the keywords/ad in a specific group as well as account settings. The specific group receives a lot more weight.
While history is important, sometimes, its highly overvalued if you have an overall successful account.