What's this wrench for?

[gjz30075]

I got this at an estate sale and was wondering if it's for a Model T or something from that era. The open end is a 9/16" and the large opening measures
2 7/16" across the flats. No markings whatsoever on the wrench.
What do you think?

I should add that it's definitely not homemade.

 

[kd3pc]

I believe it is a wrench for the "hub cap" for a late 1920's car...I had a '29 Plymouth that had one similar to remove the small hub caps.

I look forward to other posts, to see what it is.

 

[Gmonkee]

The octogon big end should be a major clue to its intended use. Look toward the early car type wrenches for sure.