Hymer replacement window handle base

All the plastic parts, specially the UV exposed parts, in my mature Hymer camper is starting to disintegrate.
Last trip I had two windows malfunction due to the window handle base (in lack of the right term) braking in several pieces when trying to open the windows.

The handle itself seems to be more robust, so here is a replacement base part.

This is a bit simplified, without the locking button. It always annoyed me anyway.
The handle is kept in place when window is open by friction alone.

The parts are held together with a 3.5x,9.5mm screw and washer.