I am now running the compressor the first time with oil.
My intention was to make all the tubing between the air oil separator and the compressor but I ended up having some fun with the compressor.
Now there is just a simple jar of oil and a container to receive the somewhat used oil.
At first the oil had a lot of metal particles in it but after runnin it for a while the amount of metal became a lot less.
At the same time the power needed to turn the compressor went down.

The video is spoken in Finnish but it has good quality hand written subtitles in English, German and Swedish.

The video is here