The 8th box should be for the Steam Whistle controller. Note that the engine wrapper is not shown in this picture. The 5358W did not include a transformer. In this era all sets with transformers hat a set number ending in WT or T.
I have visited Dennis many times over the years at his Altadena home and purchased one of the sets photgraphed for the Deger book for my personal collection. All the sets pictured were subsequently sold by Dennis to Gilbert collectors. In my first visit to Dennis’s home I saw this specific set but did not purchase it.
