I called AppliancePartsPros.com and spoke with a sales technician. After properly identifying the name of the broken part (I was not aware it was called a flipper mullion) she confirmed they had it in their inventory. Given the function of this part, I had them overnight ship it to me for a very reasonable price. It arrived the next morning by 10:00 a.m. and I installed the new mullion in under five minutes. The part was an exact match so it was a super easy installation. The French doors seal properly once again when closed and everything is back to normal.