Hey there, i made a couple more designs for missing parts:
My Parisienne was missing this knob, so i've modeled it to avoid buying whole switch. I used PETG so it's more translucent and heat resistant to pass the light through and not melt. This particular one it made for hazard light switch i have in my car, which is Roberk Model 800, however the design i made looks more like native for Impala as it doesn't have a metal part there. I'm not 100% sure Impala's has the same thread though.
Also made this part as my car is missing one and it's hard to find one. That should hold me till i find the original metal one. I don't have an actual faceplate (the one with PRNDL) for now so i'm not sure if the underneath area i matching it's shape, i tried to match the photos. Will update the model when i get the actual console faceplate to make sure it fits like a glove.
I have a printer of course. Old lower end one for a 100CAD. Modern resin printers give much better quality.
I don't have a scanner or original parts:) I just found a couple images on the internet, measured the areas which those parts supposed to be attached and modeled them in 3D Max.