The Mahendra Sagar Collection of Inverted Centers
October 5-6, 2011
| Images | Description | Current Bid |
 | Lot #542 URUGUAY 1974 Precursors of Uruguay Aeronautics, N$100 bottom sheet margin horizontal strip of four, black color printed twice, once inverted in mirror image, with a normal sheet of 20 for comparison ** Catalog #897-900var | Unsold |
