here's an interesting accessory multi-function coil box key, kind of like a minnie Swiss army knife for your T.
Could not find a patent, but this small feature in
Aug, 1918 Popular Science would indicate the
probable time frame.
Before someone asks how that thing works on a gas tank, I'll point out that I think in this case it refers to the Prestolite tank (square hole in middle of key)
Ahhh – of course – Acetylene “Gas Tank”
Now I want one for my Turbo torch and plumbers “B” tank.