| APS, (American Philatelic Society) (Prüferkommission) |
Attest |
Scott |
18 A |
| Brettl, Schmitt (Prüferkommission) |
Attest |
Michel |
18 a; GB 23 |
| Indian States Expertizing Service Inc., (ISES) (Prüferkommission) |
Attest |
Stanley Gibbons |
18 b |
| CEM, Comision de Expertos de Madrid (Prüferkommission) |
Attest |
Edifil |
18 cc |
| CEM, Comision de Expertos de Madrid (Prüferkommission) |
Attest |
Edifil |
18 cc |
| Raybaudi, Experts (Prüferkommission) |
Attest |
Sassone |
18 g |
| RPSL, Royal Philatelic Society (Prüferkommission) |
Attest |
Stanley Gibbons |
18 sa |
| Brettl, Schmitt (Prüferkommission) |
Attest |
Michel |
18; 11 |
