73 2 liter PCV valve questions, Need some help on what parts are missing Options

[Marcel Aircooled]

OK, I am trying to eliminate some possible air leak sources causing slightly higher rpm on my 1973-1974 2 liter 4 cylinder US GA code engine with D jetronic FI system.

Looking at the PCV valve I have and the Porsche parts diagram it looks like I am missing some parts. Mine is just screwed on with the white nut without any seal or o ring (#8 in below diagram) and the hose comming from the manifold is connected directly to the pcv without any elbow piece like #14 in the diagram. Also the stopper part (#9) is missing. Could the missing seal, elbow and/or stopper be causing a (small) air leak? My engine is running 100-150 rpm too high when idling and when I close the hose coming from the pcv with a pair of pliers the rpms drop to about 900.

Also my oil filler cap does not have any seal as shown in the diagram (bottom part of #2). Should there be a seal and if yes what type?

Here's a picture of the parts I have (white plastic nut is not shown)


And here's a screenshot of the Porsche parts diagram


and the part numbers


Thanks for reading and for any advise!