I found about 40 of the actual vintage ones at an electronic reclamation yard and sold them here. The ones from that era have the etched lettering. The conventional ones are more cheaply produced and have silkscreened(as I am told) lettering.
The vintage ones don't require cutting as noted in the illustration posted by jheilman. They can be tapped apart from the knob.
So...if you have a electronics junkyard in your area you may want to go check them out. Thats where I found my dials...and my proton pack Dale resistors, Clippard valves, and other interesting items.