I really prefer to keep the bank out of estate inventories as much as possible. If there are multiple executors, or an executor and an attorney managing the estate, we ask that both parties inventory the box together. If two parties are absolutely not available, a bank officer may pinch hit.
If a bank employee or a representative of the Department of Revenue are NOT conducting the inventory, there are special requirments that must be met. Do not let the executor and/or the attorney for the estate into the box without proper authorization from the Department of Revenue. Start here
http://www.revenue.state.pa.us/revenue/lib/revenue/rev-584.pdf. PA Code 72 PS 9193 covers this and the Department of Revenue Inheritance Tax Division is very helpful if you call them.
Also Profit Protection has a SDB Manual that we just purchased. It is comprehensive.