Have these on hand if you plan to remove your door panels on any of these older models
Many of these, especially along the bottom of the hard are hard and brittle and will break when removing the panel. Tilt and twist to remove and install in the holde. Sold in a bag of 24.
W108 W109 W114 W115 W123 Interior Door Panel Clips - 24 PAK
$26.00
SKU:
INT-DOORPCLIPS 
Product Details
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$28.50
1965 to 1991 Sedans and Wagons Plastic Door Liner Replacement Kit
Enough plastic and adhesive for four doors, including SEL models. Video instructions for plastic sheet replacement are included.
If you own an older Mercedes sedan or wagon, it is a very good idea to remove all four door panels, repair components, clean drains, and, most importantly, lubricate all moving parts, as Kent explains in numerous YouTube videos.