After having both calipers installed some time ago (pic 1), I decided to go one step further: more sophisticated DRO with some math (radius-diameter conversion + some memory functions and calibration of tool position).
The idea was to use Arduino UNO for reading both calipers and display on LCD with buttons for commands.
For sketch (Arduinian for "f/w") I found couple of examples on web, but I had some initial problems with pin terminology (Arduinians are strange folks with some strange ideas of how to name things). After some fiddling with the code I have basic functionality to use with my lathe.
For level converter between caliper 1.5V logic and Arduino 5V logic I used cheap
converters from ebay (LV needed to be dropped from 3.3V as suppied from UNO by means of series diode to achieve better output voltage span).
Pics 2, 3 are showing working circuit (here one caliper is used for both inputs so the displayed values are the same).
Next step is to mount the processor and LCD with buttons in the metal box and wire the whole thing to the lathe.