General observations regarding German WW1 altimeters.
With engines bolted firmly to the airframes, without any shock absorbing device to cushion the vibration, the airframe vibration level must have been quite high.
Unlike standard aviation practice for the last 75 years, the altimeters were not mounted to the airframes in a permanent manner in WWI german aircraft, but were instead installed prior to flight and removed and taken back to a safe place afterward.
The reports and autobiographies of the pilots typically show a strong awareness of their operating altitude, thus it appears that altimeters were in common use, perhaps not in every aircraft, but at least in every flight of multiple aircraft.
When mounted, altimeters were commonly supported from three points with some shock absorbing medium between them and the airframe (springs or straps.) With luck, a neat old Pleyer photo of an Alb C3 cockpit will illustrate this for me. (You experts feel free to correct my aircraft identification

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Pleyer cockpit photo
Small wrist mounted altimeters were also used.
The point I think I am trying to make is that altimeters were in common use, but were never part of the airframe. Comments?