WW1 Tycos Type D Altimeter Gauge Instrument (Extremely Rare)

Description

Up for sale is quite possibly the only surviving example of a WW1 era Tycos Type D altimeter.
I acquired this item through the estate sale of a retired USAF Major whose dad had served with the Signal Corps in WW1.
Both the gauge and its original leather case are in excellent shape considering their age.
This is more than likely the only one of these that you will ever see up for grabs.