Hi, I'm Greg. Welcome to JustAnswer. I'm reviewing your question now, and will post back with your reply ASAP.
I am happy to help on this. Since the school has been closed down, you will need to contact the current school district and ask them what the procedure would be.
Those records for the closed school should still be contained in the school district database for verification purposes.
If you go to your browser and type in the city where the school was located along with school district it should take you to the main page - look for contact information and contact the district office.
I hope this helps. Please be sure to rate when satisfied with my response as that is the only way I receive credit for my help today.