A6 3.0 TDI QUATTRO numbers

[Cwizard]

After looking at the engine of my 2006 Audi A6 3.0 TDI Quattro, i was wondering how many things were actually changed on the engine itself. As in parts. So i stumbled upon a few 'numbers' lol. If someone could tell me what they mean and what they're from i'd be forever grateful.

Here it goes:

{
Werk : 026
Date : 100806
Line: 2
Part : 059 064 CA
}


059 129 086 M > I've got 2 of those? both have years 2010 on them? I have no idea what it is nor why it was changed.


I've also managed to record some very scary things ( at least theyre scary for me ) under the hood. Seems like carbon deposit around one of the hoses, also what i believe it to be an oil leak of some sort. Will upload video in about 30 mins. I'd appreciate if someone could tell me is it anything i should be worried about or not.