hi Paul the headlight parts on early (about 47-50) AD trucks are also brass, plated with chrome, later they changed to stainless steel both the inner bulb holding ring in your photo and the outer beauty ring with the single bottom screw hole
the brass outer trim rings are one continuous ring and don't have the spot welded splice at the bottom screw location, see photo attached some of my trucks have the early brass and by 53 for sure it was stainless, i don't know what year(s) Chevy/GM transitioned to stainless. early cars headlight trim could also be chromed brass parts, i know i have also seen them at the wrecking yards. -s
