Ford tractors, modified by Wehr, I posted about them last summer http://justacarguy.blogspot.com/2017/05/wehr-power-grader.html
with a bit more info http://justacarguy.blogspot.com/2016/03/steve-comes-across-some-cool-stuff.html
https://onceuponatown.tumblr.com/post/104797095275/ford-motor-co-snow-plows-ca1915