1967 Chrysler 300 vert, rear door panel and armrest questions

All: starting on some interior stuff, and my armrests in rear are split and the plastic wraparound piece (not sure what it is called) is pretty rough. I have seen video on how to redo the plastic panel, but can the armrest be bought, or is it one large piece. I have circled, or ovaled! the piece I am talking about. Any hints would be great.
C- Shaft View attachment 418277
Author: Camshaft