I have replaced these in the past. Went to Harbor Freight and bought a spot weld drill to drill out the spot welds and then welded and riveted a replacement in place. The challenge is finding a different one that is better than what is already there. Because if it is coming from a donor sled, and it is better, that sled chassis might be the better chassis to use. We have also welded patches to the cross-braces if it was just one of the legs of the "x" that was missing.
For this photo, I am with Bob, you are probably OK with what is there, unless when you clean it up find that it disappears.