On a copy of your current data where the invoice batch was deleted:
1) Create a new invoice batch and note the Batch Number ####. Check the data folder and you will find API####D and API####H.
2) Delete the API####D and API####H that were created.
3) From your backup that has the deleted batch restore the batch that was deleted and rename them to the ones you created and then deleted.
4) Run a DIC, it should complain, rebuild and see what you get.