An unused for over 20 years ESAB THG 140 unit was recently discovered in a dry workshop storage.
Is it worth cleaning up and testing, and would it even pass safety testing these days?
As above, just plug it in & try it. It may well take the trip out the first time you try it due to the inrush of current, then be fine the next time, this is to be expected as the transformer energises, I think it is.