Cleaning out the hangar - This is a new, Electronics International, EC-1P CHT/EGT gauge. It displays one channel each of EGT and CHT.
The unit is full size for a 3 1/8 hole in the panel.
You can use a switch that EI sells to set it up as a multi-probe unit with up to six each EGT and CGT probes. The install manual explains all that.
I installed a similar unit in my Citabria using the EI switch and that works great. It makes a simple, reliable, low cost engine analyzer.
I can't remember why I bought this but I never installed it for whatever reason, probably changed direction in the project. Don't have the original box, not that it was anything special..
I only have the one EGT probe so you'll have to scare up the appropriate CHT probe for your engine.
EI stuff uses type K thermocouples for all their temperature sensing and probes are easy to come by.
Shipping is $15 by UPS ground to CONUS. AK and international by actual cost.