Its sounds like your issue is that the Merc cannot be towed on a dolly or all-wheels-down. My nieghbor has a similar problem with his BMW 745. His solution is to tow it backwards on a dolly. Yes, BMW forbids this, and I suspect that Mercedies does too. He's been doing it for years without a problem.
Towing the Merc on it's front wheels reversed? It would cause a coronary. It wouldn't clear the ground either. It sits, without measuring, about four inches off the ground.