<<ABOUT THIS MOTOR:

I don't know what these "tabs" are on the down tube - I have never seen them on any other Caille.

They are NOT for a rudder. I have seen 4 variations of Caille rudders, and none are attached using anything remotely like these tab things. They look home made to me.

When it comes to dating this Detroit motor, because it has a magneto, it is 1915 or later.

The ad on the Detroit home page shows a 1914 motor that is battery fired. Magnetos were not available that year. This motor, except for the name on the back of the tank and the exhaust, is EXACTLY like every other Caille made that year with a magneto.
The only important thing about this motor is the name on the tank, and the wonderful original condition

This is yet another badge motor made by Caille.

Trading on their good name in marine and stationary engines the Detroit Engine Works, out to maximize profits, contracted with Caille for a rowboat motor.

Below is the only ad I have bumped into, and to the right here, a typical ad for the company.

For many photos of this wonderful original Detroit CLICK HERE
or on the photo.
1914

Hunter-trader-trapper, Volume 28


also,
same ad,

1915

Recreation, Volume 52, Issue 3