That Lucas masterpiece (tongue in cheek) was designed with the best materials available in the
50s. If they lubed it at all, it was with a petroleum based product. Plenty of entry holes for dirt
and dust to leak in, especially since it's on an open car. The few that I have taken apart were
caked with what looked like Cosmoline™ It was probably just a dirt/dust and oil mix.
When I did mine, after getting everything sweaky clean, I sprayed it with the best pure (food grade)
silicone spray that I could find. That was 20 years and 90K+ top down touring with no problems.
Frank