It reads Autoster Co. Rockford, Ill. Best Steer .......have on idea or can't find anything about it??

Forgot to put size   8" tall & 6" wide

Til I dig out a 1922 accessory book, it looks to be a steering assist device from the Model T era.  The T area clamped onto the tie rod and helped keep the car going straight. 

I can offer a half-baked theory that would support the name and "Best Steer" cast into it.
Suppose that the grooved feature were attached to a crossmember or the front axle of a vehicle, and that the two arms were positioned so as to capture some part of the steering gear.  Properly positioned, any deviation from a straight line would cause the spring to oppose that change, yet a driver could easily over-ride it.  Would have only been useful in the days before power steering.  Not long ago, there were "helper" springs to add to modern steering gear for similar purposes, mostly sold as devices to prevent shimmy, and for off-road use.

Too bad that pre- early 1970s patents can only be searched by a couple of terms which do NOT include Assignee Name or Inventor City . . .

Just saw that a new post was made - and it appears to be along similar lines!

>Too bad that pre- early 1970s patents can only be searched by a couple of terms ...

Pre 1920 patents can only be searched by class and date :(
Part of the reason I decided I needed my own patent database, sadly, I don't have much past 1880 yet...

A quick search of assigned companies in Rockford brings up lots and lots of patents by Emerson Brantingham co, which makes me think we should not rule out the possability it's for centering steering on a tractor....(Spinoff company..?)