Hmmm. I think I recognize that grinder on the floor! One of the best tools the wife has ever bought me as a present! Mine been earning it's keep around here!!
Abe, the frame rail looks to be in pretty good shape. Make sure you check the pitted area really good. Don't be wimpy with it, but poke it. If you don't, you may regret it down the road. Better to repair it now then later. While I was doing mine I found some areas that were pitted, but due to the thickness of the metal, thought it'd be fine. It wasn't! It was just one more thing to fix, but I'd rather do it now! BTW, it's done now too!