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According to the Fastlane parts ordering system, you have the correct part number for the flex disc. Lemforder is a supplier to Mercedes for parts. There is no ordering sequence to tightening the bolts. Its most important that none are loose. One possibility is that fixing the front flex disc exposed a problem somewhere else. This is not uncommon. (i.e. Check the condition of your center support mount and bearing.)
I would take it to the mechanic and explain you started having a vibration after the front flex disc was changed and you'd like him to check it out. Don't assume the front flex disc was incorrectly installed. Or more importantly, don't accuse him of installing it incorrectly. Let him check it out and see what he finds.