I made one out of an old Hame end (from a draft horse harness). You can get them in chrome or brass or painted black (often brass under the paint).

I made another out of a c02 cartridge of unknown origin. A trip to the local salvage yard can yield any number of cool old items that could be modified to make a shift knob.

My Dad turned a wooden one on his lathe for his '49 and is going to make one for mine too. His is maple and cherry; mine will be purpleheart with a 5-speed shifte pattern let into it.

I like the rock idea mentioned earlier - Jeep sells them with the shift pattern sandblasted into them:

http://www.quadratec.com/products/product_search.php?pg=2&cn=Jeep+Shifter+Knobs&c=82

Craig

It is neither wealth nor splendor, but tranquility in occupation which brings happiness. - Thomas Jefferson

CK