Never knew those particular gauges to be available.  I’m quite familiar with the pressure switches that go into the oil galley but not a gauge that incorporated the same safety feature.  Undoubtedly those gauges were originally designed for the stationary and/or industrial engine applications.  Those gauges are definitely an easier to install option than the sensors that screwed into the oil galley and required some additional wiring to complete the deal.

Lorena, Texas (South of Waco)

Yes Ted they are used in stationary engines in industrial climates. The company is still in business, you can google there site. How these instruments fit into our world I’m not sure yet.
Maybe engine break-in, racing, and maybe street. I plan to instal mine but I am hung up how to set it up without having to trigger bypass switch every time. 

At one time anyone running an electric fuel pump had to have a shut off triggered by the car or engine in our racing organization. They settled on a rear bump switch like modern cars a few years later but I installed one in the oil pressure system with a 15psi cut off to the ignition. 

56 Vic, B'Ville 200 MPH Club Member, So Cal.