Oil Pressure

No there isn't, but I bet the new sender will fix the problem. 

Roger, what do you think about this?

If one increased pre-tension of the spring by adding a shim or two oil pressure would increase, I recall. Of course it would at best be a try but decreasing pre-tension (which I do not recommend) would lead to a lower level of oil pressure. One could try diffenrent springs altogether or perhaps cut of a quarter of a turn off and see what happens.
Should anyone give it a try I'd be interested to learn how much of a difference a turn of the spring cut off makes.

Peter

The spring has a preset tension just for our use so tampering with it could possibly cost you an engine. before you would even think about any alteration you would need to be absolutely sure about the gauge pressure. The majority of times the sender is the culpret for bad readings.

Remove the sender and replace it with a basic mechanical 100psi Pressure Gauge.  The type with a moving needle right on the gauge.
Pressure is Pressure.  Any gauge will work as long as the threads match.
1/8 NPT until  about 3 years ago when it changed to M10.

This will give you a reliable pressure reading to compare to your  Electronics.
It doesn't get much simpler.