We have decided to restore, which luckily we can use a copy the client happened to have made inside Sage 100 yesterday evening prior to renumbering, so they only have to rebuild one day and not two. And although the Invoice History file has all these wrong Customer #'s for 80k invoices, the invoices contain the correct Customer Name, so I was considering performing an Excel VLOOKUP against the customer file to obtain the correct customer #'s. However, we determined that a good amount of the 11,600 customers have the exact same customer name so therefore we'd have to manually address lots of invoices to determine the proper Customer #'s. Plus there's also the possibility that it's not just Invoice History that's negatively impacted.