Says  "northeast Horn wrench"

I think for adjusting electric horns

jun639 by Skip Albright, on Flickr

If the file is not too large, copy the edited " new product writeup " to go along with your wrench.
P.S.  I'm going to "snipe" the wrench pix for the MVWC Newsletter.-- Thanks.
P.P.S.  Found "North East Horn" was used on Dodge Brothers & REO automobiles -- probably others.