Erratic oil pressure gauge

Car in question is a 92 LX 5.0. 120k miles, real healthy. No leaks, no burning.

I noticed the gauge stuck at about 3/4 today while out driving. Usually, it would swing higher as I revved the motor, and go back down lower as it idled. Now, it gets stuck at 3/4 and mostly stays there, sometimes rarely it will go back down, but sort of jump around a tiny bit. I feel this isn't normal, haha- so what should I look at first? Change out the oil and the oil sending unit and see what's what? Is this a common issue with these cars?

Thanks a lot!

Oh ok, I wasn't too sure how accurate the meter was to begin with. I will start with the sender and a fresh oil change, see how that helps. If that doesn't work, I will throw a meter on the system, but I don't even think that's necessary, because the motor is so healthy and strong.

Thank you guys!