Porsche used a wooden shift knob for some of its race and sport cars, a laminated beech knob for the Carrera GT, a laminated balsa wood knob for the 908, and a laminated mahogany wood knob for the 917. I make them all with power tools (lathe, thickness sander), NO CNC machines, so every knob is unique (the photos are for illustrationpurposes, the knobs may vary).
I make the knobs with a brass insert, which allows anyone to use the original crush sleeve, and install the knob with ease on a 901 or 915 shift rod. Other fitments available (threaded early 911, Rennshift, Wevo, Hargett, G50, 964, 996, 997, 993, Boxster, 981, 991), consult me for these applications and their cost. Does NOT include the adapters or horn button in the photos, only the beech wood knob.
The finish is rubbed oil, then a preservator's wax, then its polished. Much like a fine shotgun's stock.