Steam Gauges are used primary in the 162F, Exec 90 and earlier. Most of the gauges are made by Westach.
The Enigma EFIS (glass panel) is used primarily in the early version Talons. This category also includes the Odyssey and Voyager, which some owners have fitted in place of the Enigma.
The Discovery EFIS (glass panel) is standard in the later version Talons. This category also includes the Explorer and Challenger, which essentially are the same as the Discovery, but with a larger screen.
Most gauge problems can be diagnosed with some basic tools.
You will require a multimeter. But, for out purposes, a $5 multimeter will usually work just as well as a $300 multimeter.
Then if you add a couple of 1000 ohm resistors and 3 test leads with alligator clips to your toolbox, you should be ready to diagnose most gauge problems.