1959 Mercedes Benz Ponton 180d progress , leaking compressor/injector

slow progress on the old benz, loaded new Bosch glow plugs, injector compressor n fuel lines have leaks,, watch my youtube see if u can identify a few things for me, the engine side of the injector has a fitting where fuel leaks out,,,what does this go to? the end of the injector facing the fire wall has a bolt or threaded spline..what goes there? pls comment., i am looking to buy Porsche speedsters n 911s cabriolets n coupes , any condition , rusted wrecks , chasis, let me know [e-mail]