The clamp we used to use was more like a lighting clamp. It had a bolt on the bottom, you installed a clamp on ring to the wire, can't remember the correct term, then you bolted it to the clamp. Would that be code compliant?
No, it was just like a lighting clamp, the bolt that would go to the yoke, had an eye type brass connector that crimped to the grounding wire. I don't have a clue where to find a picture.
Looks like a genny ground clamp. If you're using a genny along with the house's electrical system, you should ground the genny with a ground rod and connect to the buidling's ground as well (to put both on the same ground plane). That could connect the genny's ground to building ground.