My apologies, I was having a bit of trouble understanding the data.
I would then not call those duplicates. Each product is unique in QuickBooks. They might have the same name in Salesforce ( we will get to this in a bit) , but they are uniquely represented in QuickBooks.
It is very possible that one of those items was renamed in QuickBooks and set to inactive. Please remember that DataSynch will not synch inactive QuickBooks Items.
It is also possible that the QuickBooks Item was created, synched, and then later deleted from QuickBooks.
The newly created Product in Salesforce is most likely the accurate QuickBooks item.