Letters character is not German also no WaffenAmt stamps, German was more signed, in 500 meters radius I found American and Canadian made parts.I don't know much about aviation but the characters in the upper left look like a German font to me. Especially the number "4".
do you have some pictures to compare? I found American and Canadian made parts in 500 meter radiusThe "car 43" you see in the rectangular box is the makers code for Eisenwerk Weserhutte A.G., vorm Leobersdorfer Mascinenfabriks A.G. Leobersdorf bei Wien It. 5 Nachtrag, and dated 1943.
Assuming it's an airplane part, what would be measured on a scale of 1 to 5? How about the force of gravity, in G's? Might be the face of a G-meter.
IMHO it is 8/16 (fraction) which is 1/2 or 50% of the full unit. It's only shown like this, not as 1/2, because the 1/16 is probably the important unit. We don't see the center part of the dial - maybe the units were written there. I was thinking what is 1/16 of a litre for example = 62.5mL. If this is per hour or per minute, this might be some specific liquid. Note that the odd and even positions on the dial are marked differently to make the reading easier. I think there was one hand only.I would suspect, if we could see the hands, they could go around twice with one hand point to the lower number and the primary hand pointing to the higher number. I.E. 16 is twice 8 rather than a fraction.
The item in the other image in post #1 isn't an aircraft part. Looks like a fuse of some sort. Writing on it says CAP 25AMP 115V / 15AMP 230V AC.
Are we sure that the other item is even an aircraft part?
None of which are normally fitted with a gauge. Just a dipstick on some and the rest you fill to the top or the line on the sight glass.Possible.
Windshield wiper fluid.
Oil load for a small(ish) aircraft engine, or an auxiliary long range oil tank.
Fuel for an auxiliary generator.