1927 Russell Grader.
Fullsize image: https://diqn32j8nouaz.cloudfront.net...r_fullsize.jpg
https://diqn32j8nouaz.cloudfront.net...ell_grader.jpg
More: https://www.caterpillar.com/en/news/...years-ago.html
Previously:
https://www.homemadetools.net/forum/...540#post139409
https://www.homemadetools.net/forum/...396#post161930
https://www.homemadetools.net/forum/...345#post158165
https://www.homemadetools.net/forum/...338#post116485
