The Quonset hut doesn’t bother me as much as the dents they put in pole barn metal. Two different places the metal is tore.
It’s hard to come by. I would watch for bridge jobs. They almost always put new guardrail up with a new bridge. You could also check with the county garage or state highway department
I used to buy all mine off a guy named Vondy Jude, but he hasn't been responding to my calls for a while!