Hi Cees, I don't know if mine is brass, I just gave my bumpers, hupcaps and frontgrille ( stars and wings ) to a company, I bought a new frame.
I paid ca. 900 dollars for the recrome in total, and I think ca. 30 dollars pr. hupcap, but the hupcaps are not nice done, due to that they are difficult to polish.
So I will exchange them for some new ones at pagodenteile.de, as I remember they cost 49 Euros pr. hub caps.
Christian Cortéz-Campos
280 SL 1969 anthracite 172, with red inteior.