Hi Tim,
I have a copy of the wireless manual for fitting the No 19, 19HP, 19/19, 19 HP./19 in Trucks 15CWT 4x4 Personnel (White Scout Car) and Half tracks.
It is nearly all about the White. It has fold out pages with a multitude of wiring possibilities.
I also have a C15TA, so would be interested in your data.
Send me a PM. I am away from a computer untill Wed pm.