oil breather

Anyone know if there should be any or how much oil in the rocker cover pipe leading into the turbo air intake pipe? When inspecting I found there to be a fair bit dripping out, there is also some residue coming out of the turbo pressure gauge nipple. Any thoughts would be a help.

Can any one shed any light on how they have hooked up a oil catch can on their 2.5 TDI? I want to fit a catch can on my 2.4 AAB turbo conversion and wanted some info or advice on how you have plumbed it in? Any info on ID of original breather pipe of an AAB etc or any pics would be great...