That box reminds me of the one I received a while back that was filled with little tiny pieces of glass rubble. It was a do-it-your Mangusta window kit. Unfortunately I had the wrong glue (none was supplied in the kit) and out-of-date model-building skills, so the end result was less than impressive. I finally had to re-order a fully assembled one to replace it. You got lucky!
Just for the record, FedEx "Ground" seems to be staffed by ex UPS workers, managed by ex USPS managers...(or subcontracted entirely to UPS?) and can (in my experience) produce startlingly similar results!
Mark