My first attempt was the Caddy lights adapted to the stock Drifter light housings. It was easy to mount them, but the end result was not good. The Caddy light is just too much overhung load for the stock light to handle. Over time the plastic/rubber on the light failed and I lost the light.
My second attempt was using Greenbarn's modification. It worked perfectly. The lights and extensions that he recommended were readily available (eBay). The aluminum adapter was easy to make. The only additional step that I took was a modification to the stock bushing that the bolt for the light goes through.
The stock bushing only allows you to tighten the light mounting bolt to the point that it bottoms out on the bushing. This still allowed the light and bushing to pivot within the mount. I found that if I ground off a little of the bushing making it shorter, that you could tighten the bolt enough to compress more of the rubber bushing. This really tightens up the light and keeps it from swiveling under it's own weight.
Many thanks to Greenbarn for figuring out the hard stuff and making it available to us!