Thanks very much for taking the time to respond, the gaskets are original and were purchased from Mercedes Benz, the bolts are also the original ones, but that was good advise you gave me regarding the washers and I will certainly replace them, the gasket did not come with any washers, do you know exactly what size washers are they, or can I just purchase any copper washers that fit, you made a very important observation when you pointed out
"In your pictures above, it doesn't even look like the cover is torqued down. Is there something obstructing it? I can see space between the gasket and cover."
You are absolutely right about the space between the gasket and the cover, I was wondering about those spaces and now that you mention about torque, I am now wondering that there is a possibility that the mechanic did not correctly torque the screws, so I will be sure to torque them to the correct measurement which I understand is 9nm. Thanks again for your recommendations and advise against using a sealant.