I couldn't find a closeup picture of the end of the rod treatment I mentioned but this picture comes close. In this case they ran the finished ends to an adapter plate (which I think is a good idea). Looks like a crimped end, then drilled for a fastener. Andy, include a link to the tabs you reference SVP. I'm going to take a picture of a no-name steel rack I've got to show the dropout attachment points and how they are fabricated.