The oiler design is interesting in that it drips upwards, apparently through liquid that does not mix with oil (water ?).
I have seen the "drip upwards through water" oilers on steam engines, but was not aware that they were used on IC engines.
I am not positive how that oiler gets the oil up and over to the various places after it drips upwards.
Here is a steam engine lubricator, which drips upwards through water in a sight glass.
The rate of oil flow can be seen throught the window in the form of the speed of dripping.
And a positive oil flow can be verified to each area that needs oiling by observing the dripping through the windows.
If one of the oil pumps stopped working, you would not necessarily be aware of no oil flow without having the windows for visual verification.
https://www.youtube.com/watch?v=SyI4wozVb94
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