So, the workbench was just made of plain pine lumber and that wasn't really going to last very long especially for a metalwork bench.
I occasionally use a welding machine and that can lead to pockmarks from molten droplets of steel spattering here and there into the surface.

I did not have any large sheets of steel on hand to fasten to the surface of the workbench, but my neighbor did have a bunch of these square plates with four holes in them that were once nailed to hardwood lumber.

The plates- I don't really recall what they were for- had a lip bent into it to form a 90 degree angle. I assume that was for stacking, but there were a lot of them and all I had to do was flatten them out. I took 35 of the things in total and heated them up one by one to bend them back flat.

After that was all done and they were cool to the touch I went on and countersunk all 140 of the holes and screw them to the surface of my work bench, to get a really neat improvised steel surface.