It's common for the head gasket to fail near the #1 exhaust port with oil dripping on the chain tensioner and alternator, not to mention leaking into #1 and sometimes #2 cylinders. A coolant breach of the head gasket is a separate issue that seems to occur around the #4 cylinder. Oil pooling by the Garrett wastegate arm is more likely from the turbo oil supply junction atop the center section of the turbo. I don't think you can see a KKK wastegate arm so I'll assume you have a Garrett.

The trick is to determine whether the water pump failed on its own or the seal blew as a result of excessive coolant system pressure. The water pump should hold better than the system's 1.4 bar rating, though.

Sixto
87 300D