You are wasting your time and effort trying to get a copy of your 2013 income tax return. The inheritance will not be on your tax return because you do not report an inheritance on your income tax return. The person who told you to look at the income tax return doesn't know much about income taxes.
If you don't have your bank statements or any other records from 2013, your best hope is to ask your bank if they have a record of the transaction. If they don't, ask NYL how they know that you cashed the check. Ask NYL to send you a copy of the front and back of the canceled check. The back of the check will show if you endorsed it, and what bank you deposited it in.
