Sad story. The good news is that you now have a good starting point for a nice project. I would find a rusted out W108 4.5 in good working order for cheap and transfer engine, trans, brakes, rear axles atc. as needed. It's all mostly bolt on. Good thing with the 4.5 is that you can fit it with a manual trans (out of a 3.5 if you find one).