I have had this wrench for a long time and could never figure out what this wrench was designed for, or who made it. It is marked 2810.
(http://i418.photobucket.com/albums/pp267%3Cbr%20/%3E/blackoakbucket/6eac0466-05df-4232-a07d-%3Cbr%20/%3Ecb8896c1d5b0_zpse447ebf9.jpg) (http://s418.photobucket.com/user/blackoakbucket/media/6eac0466-05df-4232-a07d-cb8896c1d5b0_zpse447ebf9.jpg.html)
(http://i418.photobucket.com/albums/pp267/blackoakbucket/101_1641_zps74d6e545.jpg) (http://s418.photobucket.com/user/blackoakbucket/media/101_1641_zps74d6e545.jpg.html)
Looks like a Z810 pitman wrench for a IHC mower(horse drawn). we've had discussions about pitman arms on Tool Talk before.
Jim is right. It's and International Harvester mower pitman wrench. The number is Z810.
Thanks guys for this info. No wonder I could not find anything on it searching 2810 instead of Z810.