Bob's information is correct. When they were looking for an additive in the early 20's, the reason was to increase compression in engines. They had no "lubrication" intent. Most of the myth stuff alludes to the depositiion of lead "to prevent wear"......reason would suggest that lead is soft and would not wear well (engine bearings are not contact wear items).

Here is a link with some history:

http://www.chm.bris.ac.uk/motm/leadtet/leadh.htm

You arent going to pull up to a pump in the USA and get leaded gas out of a hose.....no matter where you live. Federal Law took care of that years ago. Maybe out of a 55 gal drum but not the pump.