| Issuer | Date | Desc | State | ||
| - | no image | Liberia | 2/26/1968 | empty sheet (#34205) | incomplete |
| - | no image | Liberia | 7/11/1968 | empty sheet (#34206) | incomplete |
| - | no image | Liberia | 8/22/1968 | empty sheet (#34207) | incomplete |
| - | no image | Liberia | 12/30/1968 | empty sheet (#34208) | incomplete |