Viewing filed payroll returns in company file restored from client backup
The saved forms (payroll returns) are not saved inside the QuickBooks company file but will be on your client's hard drive. They are not considered data and so are saved in various folders based on the form itself.
The usual location is C:\Users\Public\Documents\Intuit\QuickBooks\Company Files\[companyname] Tax Form History\INWKS[taxfrom#]\[year and quarter ending]
Have your client open the ones you need and save them as pdf to send you.