Oil from the turbo seal on the inlet side of the turbo is not going to make it through the combustion chambers and remain a liquid in my opinion. To rule it out remove the connecting tube between turbo and enginne intake and check for excess oil present. If originating from the turbo spread over several if not all cylinders it is going to burn up in the engine and come out as all smoke in my opinion.
Oil pouring into one cylinder is a different proposition. Head gasket is more likely again in my opinion.
Do the cold hard hose test as well. Make sure the system will hold pressure first. You could check for an oily cylinder or extremely carboned up one. Also a compression test may give some kind of indication. Look for problems in the number one cylinder as there is a pressure oil passage just in front of it. The above is just how I would approach the problem as I do not own one of these engines. Combined with hopefully common sense and limited knowledge.
I do not think it is coolant in the exhaust but might be if a head crack was bad enough and present. The hard radiator hose should give that away when cold again. Others that have actual experience with this particular engine will post a clearer picture for you I hope.
I also thought your head #20 was not bad if a twenty? Or am I getting the numbers off the posted ones wrong. Is it a # 16 instead?