Jeff, It looks like you have had your questions answered. If the non-drive side of your hub is threaded, you only have the Arai brake as a possibility. And, it is the only real drag brake. Like I said, I would recommend looking for an Arai brake, because they can still be found. They will be harder and harder to find and the cost more dear, as time goes on. If you decide that it isn't for you, you can always sell it. This is just my opinion, but if I lived and rode in your area, I would not debate it; I would get a brake! It, in my estimation, adds about 1 lb. to the bike, but would be worth it to me. Again, my recommendation would be to get an old style thumb shifter or a bar con, set in the friction mode, for control.
Newer bikes with large diameter disc brakes have made this a non-issue.