W210 wagon roof rail crossbar attachment
 

I happened upon a pair of W210 roof rail crossbars but I don't have the attachment hardware. Can someone share a description or picture of the smaller parts that hold the crossbars to the roof rails? These crossbars end flush with the rails. They don't sit over the rails or extend beyond the rails. This is a vanity project. The Suburban carries the big stuff.

Sixto
83 300SD
97 E320 wagon