Posted 4 years ago
What is it? Its really heavy, big, cool. Thanks for your help! My imagination tells me it could be used to tighten tracks on a tank? All I can find about Duff relates to jacks and this seems to be an antijack.
Similar models made by simplex.
Modern versions are advertised as useful tools for welding shops, likely to hold material together while welding or spread parts?
Update 11/25/18: it is a sill straightener patented by Duff Manufacturing in 1923-1925. Google Patents: Sill Straightener.