OK, pictured below is my $8.00 garage sale find of the day. It's got to be 50-80 years old if it's a day, and it's made out of thin strap iron bolted together with round-headed stove bolts and square nuts. It's rather rickety and I don't imagine it will be robust enough for anything except possibly weeding in already-tilled soil or perhaps decompacting lightly-compacted soils; it's certainly not robust enough to break sod.
Even so, I think it's rather nifty. There doesn't seem to be a lot of information on the web about hand plow history or uses, but then again, perhaps I don't know where to look.
A mere stripling youngster.... Mine is wooden and at least 100. Got it at an auction for $5. It has cultivator hooks, not a plow, and it is work to push it through root masses. I am too lazy to try it on sod, and it probably wouldn't work, but it makes quick work of cultivating in a garden.
Awesome! I am only guessing at the age of mine based on my ill-formed notions of when they stopped routinely using square nuts on things.
Mine really isn't so stout that pushing harder would accomplish any more, but this is in the category of tool that makes you wonder: how much more useful would it be in the hands of a strapping young fellow with real hay-stacking and pitchforking muscles?