Germany: Liegnitz Airpost Semi-Postal. Are They Authentic?

I'm following an auction that I expect will be of interest to our German stamp specialists.

I realize how difficult is can be to verify an item as authentic simply by looking at a picture, but I thought I'd ask anyways.

Do these look authentic? Current catalogue value? Bid or back away?

Brian

http://www.kmphilately.com/index.php?a=2&b=9387463

Liegnitez Flugpost

These were special postage for use on trips by the Zeppelin Saxony between Liegnitz, Breslau, Frankenstein, and Haida. Issued 3 November 1913. Lithograpy printed, perf 11 1/2.

Catalog values (MNH/MH):

Red-brown on yellow -- Michel 11a (€1,200/€700), Sieger 8a (€1,000/€600)
Brown on yellow -- Michel 11b (€1,800/€1,000), Sieger 8b (€1,150/€950)

Almost all currently available copies are Barz reprints. The reprints are available with and without a signature on the rear consisting of "Barz & Co" in a circle. The reprints were printed in sheets of 10, with the stamps in positions 4 and 8 having rounded top-left corners.

Reprint red brown on yellow -- Michel 11a ND (€6/€2), Sieger 8a ND (€12/€12)
Reprint brown on yellow -- Michel 11b ND (€6/€2), Sieger 8b ND (€12/€12)

Also, comparing the two pictured to the photo in Sieger, the number of perfs don't appear to match the originals.

Rhein und Main Flugpost

Originals are typography, perf 11 1/2.

10 Pf -- Michel I (€30/€8), Sieger 1 (€30/€10)
20 Pf -- Michel II (€70/€20), Sieger 2 (€60/€25)
30 Pf -- Michel III (€130/€45), Sieger 3 (€150/€75)

Tough to tell if these are real or not. I don't see anything that screams "FAKE!".