I know that this post was started OVER a year ago. But for those using the search, maybe this might help. Installing a kit tank on a Chopper ....this is how I did it and makes for a clean neat instillation. I, used angle iron I had but you can use (4) 90 degree angle brackets from somewhere like Lowe's. Something like in the picture. I slide the bracket over the gas tank studs, snug them down, mark where on the frame is best suited, and drill a hole for a machine screw. Have never had a problem of coming loose. Used lock nuts on the studs, and you can use lock tite on the machine screws. I cut the excess off the studs.
And that is a great looking bike, I know you have many hours in your tank.