Oil Pressure Gauge
The gauge read 40psi with key on engine off and 80psi when running. PO replaced sending unit right before we showed up and did not fix problem.
Once I got it home, I ohmed out the sending unit with engine off and got 240 ohms. I also tested this at gauge and received the same value. Did the same while boat was running and recieved 100 ohms at both locations. So I assumed gauge was bad.
So I bought this gauge which is the closest match I found:
Teleflex 30180 Prism Series Boat Oil PSI Gauge
It's 95% correct, the lens and bezel is different and does not have the star on the face: