I found some pictures of my later type one. I can't say for sure if the ally brackets on mine are the original ones but they look factory made. They do fasten to the top yoke with a single bolt each. I can't see any tabs on the headlamp "U" that might be fairing mounts?
You can see the moulded hooks that engage on grommets inside the headlamp brackets on the back of the indicator mounting bolts.
I removed mine before ever riding it and discovered that it had been rubbing on the instrument binnacle and had rubbed off a couple of patches of the "soft coat", (since replaced).
That might indicate that the brackets were not standard? But something to look out for anyway.
If I remember correctly the early steel fairing brackets go on the yoke pinch bolts with little spacers?