A Mazda 323 sensors would probably work, but you would still be looking at finding used parts off a 20 year old car.
The sensor is a one wire unit, looks like a variable resistance. That wire goes directly to the dash cluster, straight to the meter. If it screws into the hole, and is a one-wire sensor, it would work, with the only question being if the gauge accurately reflects true low and true high oil pressure. Its just a resistor, no harm could come with trying other sensors.
I don't have the specs on what our meter measures under various pressures, but this might be dug up somewhere, and compared to other sensor types. If I find it, I'll share the info.
You said it yourself, these sensors are all over the place on accuracy. I know that heat kills electronic components eventually, and a part screwed into the block of an engine stands a good chance of failing eventually, or at least going intermittent...Chris