I have a few of these which have some (very) slight almost dust-like scuff marks on the textured aluminium surface, they don’t quite meet my standards. Out they go cheap.
A very nice vintage style bakelite type black with aluminium inlay, approx 33mm total width (measured at the widest point), 16mm high.
6mm round shaft with grub screw can fit D type or splined shafts (tip: if using a split splined shaft with a grub-screw type knob you should align the split with the screw that way the screw does not compress the shaft pushing it off-center).
Very nice appearance, finger grips make this a good choice for fine adjustment and would also work well for rotary switches which require more torque than a potentiometer or encoder.
See my other knobs in various sizes:
283.mytrademe.info
Rotary encoders too:
283.mytrademe.info