The link with a copper plating is a press on link. This does require a special tool OR someone very!!! handy with hammers to peen over the PINS on the link.
This is the only style link available at dealers! YOU might try PARTSSHOP on this site as I'm sure they can get OE parts & maybe even the old style masterlink that has small e-clips.
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)