Finally got that lock off of there. My father-in-law had come by with his friend to remove it. We had first gone by the tire center which lost the original key. In an attempt to finally be rid of us, they gave us a spare key to try. It didn't fit, of course, but we used it in our welding. The welding didn't go very well. His friend with the welder tried pulling the lock too early, before they got a solid weld around, and the key simply snapped off. Then the welder quit working so we decided to try forcing different sockets on there. With that we got that lock loose.
After we got the spare on there, I took it to a different tire place and had all the locks removed, the tires replaced too. At that second tire place, they actually had a key that fit.