I bought my rocker end caps and the jack point hole from the Mercedes classic center and found them to be competitive in price to Miller Benz and cheaper than K&K. If you are a member of MBCA they give you a discount of 10 or 15% I believe the end cap was around $35.00
http://www.benzworld.org/forums/r-c107-sl-slc-class/1454502-1985-500sl-rust-repair-restoration-project.html#post3565671