I've only converted w124 but there should be holes for European wipers on the molded bracket below the headlight assembly. If you want to retain the wiper system, you will need the longer Euro wiper assemblies. If not, they are covered by the lower sheetmetal panel without wiper or squirter jet holes. The headlight conversion should have instructions, wiring diagram, and a parts list for what you will need.

The screws are secure enough once the 3 OEM screw brackets are transferred to the plastic housing assembly.