Yes, they are listed in my 1998/99 Michel Europa-Katalog Ost.
There is the following note:
Entwertung mit besonderem Zweikreisstegstempel, Datum handschriftlich, Tatsaechlicher Postverkauf nicht nachgewiesen.or something like
Cancelled with special two-ring cancel, date handwritten. Actual sale (or maybe sales) not established.
Michel's numbers printed are very low indeed: 15k perf 1500, 15k imperf 500, 30k 200.
Here's a useful web page on this issue with lots of examples and history (and some conflicting information on numbers):
http://www.aurorexchp.net/?side=Eleja