>> Check the account numbers shown on the Forms 1099-R.
Both 1099-Rs show Mom's same SEP-IRA account number. There is no other account number shown (not a temporary inherited IRA nor Dad's original SEP IRA).
The transaction history for Mom's SEP IRA online implies funds were transferred directly from Dad's SEP IRA to Mom's, based on the "Description" field which includes his account number for the transaction that credits Mom's SEP IRA. Of course, the Description field is a freeform field where anything can be typed by brokerage employees, as opposed to a structured account number field. So it might be fudged to simplify things, though I doubt it.
