You had us worried with that scrap bin comment.
I can see how that wedge would come in handy in the steel fabrication trade.Most fabricators have a couple in their toolbox. That length seems a little long to me,normal length would be in the 8' 12' to range.
Back in the 70's and 80's a lot of building columns only had two base plate bolts,we used wedges similar to that on the 2 other sides to stabilize the column until things were all tied in,again the ones we used were only about a foot long x about 2' thick on the big end. Most buildings that I've had any thing to do with in the last 20 years or so all had 4 bolt base plates.
I could see that, now that you mentioned what it may have been used for; i wish we would've had some 2 years back. Myself running a crew of 12 put up 6 freestalls and one milking parlor in 6 months, on the freestalls like you said all if the main outside supports were either 4/6/8 bolt but the inner supports sat a 3 foot tall poured concrete knee walls and they were only 2 bolt, I could see how a few of those wedges and a couple magnetic levels could of make our lives a whole lot easier, the top of the poured knee wall were never totally flat and the 6 inch pole 20/30 foot tall would wobble around till the purlins were in place. Don't do that work anymore but if I did. :-) O yah.
I think this would be overkill in that situation and since this was found with farming tools .... well thinking that it may have had another use, but to be honest; who knows for sure. The man did build poured concrete silos, wondering if they would use this these to tighten the circle rebar the held the wood forms in place. Hmmm
Interesting, thanks for reply, keeps us thinking.