Question Regarding German Airmail Stamp Scott C2A

Hi

Scott Catalog contains annotation that this stamp is ungummed. Does the presence of gum on the stamp suggest that it isn't authentic?

Interesting. Look forward to see what the experts say.
Your paper looks cream to me, whilst my perfed example is white paper.
Maybe it is the scanner settings.

Color is pretty much as it appears. Color of paper on the front of the stamp is lighter. I believe the cream color on the back is due to the gum. I've heard of stamps being regummed but lack the expertise to distinguish that feature.

The imperforate variety of that stamp is only known without gum (and it's rare, cataloging in Michel for €2,500).

Yours is likely a normal copy with the perfs trimmed off. As you can see from this image of your copy overlaid over a perf copy, there's plenty of room for trimming.

If it is Mi.Nr. 112U With the cloudy paper imperf,I Don't see why it should have gum because
112U has no gum.then it's 112z perfed variety with trimmed perfs.These stamps had fairly
large margins..The other explanation is printers waste..

Reinhard fischer auction- cloudy paper type Mi.Nr.112z

I have copies of the perf variety. The imperf copy I have is a totally different type of paper. Much thinner and stiffer paper. Paper is of the type used on those commemorative sheets of imperf US Stamps from the 1930's.

Felzmann auction: Mi.Nr. 112U OR imperf (border copy).

After studying multiple examples of the perf variety and comparing them to the imperf copy I have my confidence in paper difference has diminished to the point of extreme doubt that any difference exists at all. I am now of the opinion that the most likely explanation is my imperf example is actually a trimmed stamp. The presence of gum being the biggest clue that this was originally a perf stamp. I'm guessing whoever trimmed it was looking for a space filler for their album. If their intent was to deceive I imagine they would have soaked the gum off instead of leaving it. Thanks everyone for your input. Knowledge is cumulative in this hobby. I'm still accumulating valuable information from all of you.