I don’t know if Florida allows private party transfers without registration or not. In many states not going thru a FFL would make it an illegal transfer.
I know in Georgia you don’t need an FFL for a private party sale. And I’m pretty sure that’s the way it is in most ‘gun friendly’ states, which Indiana is. When firearms are shipped, technically, they have to be shipped to an FFL, who will then do a NICS check on you, like when you guy from Gunbroker, BW Outfitters, etc. An FFL holder will only ship to another FFL holder. But nothing prevents you from selling a gun to one of your buddies.
Please name them. I don't think it's more than a few.
PS - The transfer occurred in Indiana.