The diffusion was a good idea. I need to rebuild my Sunnex lamp, with halogen lamp, and the factory has a few options to get concerning the lense and reflector. You'd think the other makers would've considered such. In your case, all you need to do is order another cover, if you needed to replace it. When I photographed some machines a friend used to make, so as to avoid the glare of aluminum wheels, all I did was cover the lamps with paper towels, and go to work. It worked like a charm. Of course, a high heat might pose a fire hazard, so we watched what we did. Simple things can often be the best things to do.
That looks good, Barry. To me, the nemesis of LED ring lights are the pinpoints of light reflected from shiny surfaces. Your "after" results look a helluva lot better than the "before" photo. I've tried many things including a piece of baker's parchment for a diffuser which works pretty well for lights that don't have a plastic cover that can be bead blasted.
Leonardo has also mastered diffusion really well with his Artesia LED ring light.