Well, it’s not like you gave us a whole lot of information, bub. Heck you don’t even know the person’s name.
Can you give us a link to at least one of the drawings? take a photo, scan it in, something. I’m not really sure what a “mechanical landscape” is. A horizon of factories? Nothing but robots? A car junk pile?
Why do you think these were from the late 1950s?
Any idea if he is American, British, French? Italian? Japanese? Russian? That might help too.