Ancient Incandescent Fixture (1)

I got this from my construction teacher. It was filthy when I got it so I took it home this weekend and scrubbed the porcelain-glazed reflector with a Mr. Clean Magic Eraser and the rest of it was scrubbed with a steel wool pad. The piece inside is really nice brass but it's totally concealed. The top part mounted to a junction box and swivels so the light will be level is mounted on an angled ceiling.

I was told this came out of a 1920s building. The wires that came out of this were both natural-colored cloth (tanish yellow in color) so you couldn't tell hot from neutral but one screw terminal was brass and the other was aluminum. The brass screw went to the socket contact as always... Does this appear to be a 1920s fixture? It certainly looks old and was filthy beyond belief but now it's all cleaned up and has new wires since the old wires were so brittle the insulation was falling off from being touched. The cloth surrounded a small layer of tiny black gravel-like rock things, which surrounded the strnaded copper wire. At any rate, the two wires had to go so I stuck some 14AWG stranded wire I had left over from my street light stand project.