Hello,I have been researching PCV system on my series 3 e-type. It seems that the crankcase breather filter is the supplier for crankcase pressure. I have removed all breather pipes to clean deposits of oil. I noticed that at the end of each tube there is a reduced orifice before they go into the hose attached to each stromberg.I assume this is to regulate the removal of the crankcase pressure. At the front srtromberg on A-bank there is another small brass aperture with a conical mesh filter, cone shaped behind the aperture? This is supposed to be connected to a engine breather pipe ? Can anyone clarify where this hose C34929 originates? The hose is no longer available.I am trying to understand the process for the PCV in general. Any comments would be greatly appreciated. Robert