| Image Thumbs | |
| Cert Num | 1256634 |
| Cert Date | 2012-10-24 |
| Catalog Number | C23 |
| Country | USA |
| Year | 1938 |
| Denom | 6c |
| Color | Dark blue & carmine |
| Grade | Ungraded |
| Description | Used |
| Opinion | it is a genuine usage of a center line block of four tied on a Corona, Calif. airfield dedication cover by a machine cancel dated May 7, 1939 with event cachet on reverse. |
| Cert Link | http://psestamp.com/Cert/1256634 |