[AccessD] Fixing Orphaned Rows

I'm doing some work on an Access db. Some information about some persons is
deemed confidential. Before sending me the db, the client deleted those
persons. Because the original "developer" (not a db professional) pretty
much ignored the rules of RI, rows in other tables are now orphaned.

The PK in the persons table is AutoNumber. My question is this: is there
some way that I can re-add rows to the Persons table and assign the numbers
that correspond to the rows that were deleted? (I can fill in the names
with junk for the time being.)

I realize that I could change the PK from AutoNum to LongInt, then manually
add the missing rows, but once I've done that will I be able to change the
column back to AutoNum? Or is there a better way to handle this?

TIA,

Arthur