I'm finally on the Drew bandwagon, the second picture scares the shit out of me, about 10 years ago I was following a Harley when his custom made foot peg bracket came loose and it dug into the asphalt catapulting him & his bike into a ditch, if your homemade Oakie hitch happens to come down and something digs into the asphalt that's the image I see when I look at the pictures
The part connected to your bike shouldn't be connected to the swingarm(that's the part that bounces on the road, it should be mounted to the part where your shock will take the blows.............. I'm just trying to help..... Take a look at some factory mc trailers hookups to see how they're attached to the bike...........