I ended up 3D printing an adapter. I'll take a pic of it when I get home. I used it once, it fits, but is tight and needs to be sanded down a little to widen it out. Last filter change I just used a rubber strap wrench. Similar to what you posted a pic of, that works even better.
Here are a couple pics of my CAD model.
53.7 KB Views: 65
63.8 KB Views: 73