ebay don't have invoice numbers on sold items as far as I am aware.
The system runs on item numbers.
Go to sold and select 60 days if you need.
Select view order details if you have already sent an invoice and you can print that out.
If you haven't sent one yet select send invoice and that has a printer version.
(I admire what you are doing and your hubby would be proud. Your feedback is impeccable in what has become a tougher arena for sellers, good on you) 
