Hi David,
We actually tackled the issue with duplicated content being reported to Google in this forum post Tackling Potential Content Duplication Issues in Your WebStore
Basically and as explained in that post, you will need to add some nitroscript commands in your header template to allow us to correctly report the relationship between listing pages.
Please update your template accordingly or if you need further assistance with that process, we will be delighted to help you out!
Have a great weekend.
Regards,
Franclin