A circa-2014 layout shows alterations done since 1982. As mentioned, the Gayfer's store was expanded and "Dillard-ized" in the late '90s.  An adjacent strip complex, THE SHOPPES AT PANAMA CITY MALL, was completed in 2004. With these modifications, the mall proper spanned 605,100 leasable square feet.

We regret to add, at this juncture, that PANAMA CITY MALL has been shuttered "for the foreseeable future". The complex sustained catastrophic damage from Hurricane Michael in October 2018. It has been determined that the cost of repairs would be greater than the value of a reconstructed shopping center.
Graphic from https://www.panamacity-mall.com

Sears, the mall's first operational store, went on to anchor the complex for 42 years. The building was severely damaged by Hurricane Michael. Like the mall proper, it never re-opened. Dillard's, on the other hand, was back in business one week after the storm. J.C. Penney returned in August 2019.
Photo from https://www.panamacity-mall.com