There's also a third type of lugnut for the pre-1970 504 steel wheel. I don't have a picture of that.
Update: I do have a picture now.
On the left, is the standard alloy lugnut. Next to it the standard steelie lugnut. Third from the left (and this is a guess on my part) is an alternate version for the alloy wheels. On the far right is the lugnut for the very early 504 wheels.
Edited by edrach, 15 January 2011 - 04:13 PM.