I got an old compressor and it had snapped off air intakes and oil filler bung.
I drew and printed a replacement.
The thread is ISO 20x2.5
https://www.youtube.com/watch?v=_QGmLbGq-2o
video of assembly and install
No supports, any resolution (0.2 is fine)
PLA is fine, ABS might be better if your compressor gets very hot.
The author hasn't provided the model origin yet.