Yes, they're from Acerbis hand guards. Does anyone think I need the ring that came with the anchor? I'm not sure what it is other than a spacer, and none of the replacement anchors I've found online include it. The full kits from Acerbis do, but at $50, I passed.
They have the threaded inserts at FormaThread, though they're not solid like the ones in the link. It looked like the M8 x 1.25mm insert would fit, but they didn't have any installation tools, or the correct tap size.