Compressor Question

[Seadog]

It's very satisfying making replacement, or lost small parts.

 

[Erie Fred]

There is indeed a sight glass. The oil looks pretty murky but just within the limits. I’m assuming the oil level needs to be somewhere in the red circle?

View attachment 410071

Murky not good.
Compressor oil is Non detergent, as the pump has no filter, the oil is supposed to drop the dirt out, in the bottom of the sump.
Yours is loaded with dirt enough to be held in suspension (or someone dumped in detergent oil) either way, it needs changed straight away.