Michael,
I doubt that alloy castings of that thin a section would be strong enough. I have just looked through my factory list of components used on the 'Plus', and it shows the stub assembly as a fabricated part (Number SA2758) and the individual items as 38016 (flange) and 38017 (stub pipe) - both in mild steel. Both LH and RH being the same.
Hope this helps,
Regards,
Eddie.