My car did not have a gear shift knob when I got it. I tried to get a replacement with the 3 speed pattern, but ended up with a generic knob without a shift pattern.
In November of 2010 another junked 1960 Corvair appeared and I was given the shift knob. After 50 years of weathering, it was not in good shape, but restorable.
I cleaned up the grooves and numbers with my knife and a sewing needle, then filled the grooves with about 5 coats of white model enamel, scraping off the excess after each coat.
The next step was sand and polish it, starting with 220 paper, progressing to 400, 500 and 1500 grit, leaving an almost new appearance. Then I took it to Tarija where I have my buffer and a stick of polishing compound for Plexiglass. A few more minutes and it was ready for show.