| MEPSI, Mexico Elmhurst Philatelic Society Inter (Prüferkommission) |
Attest |
Scott |
51 |
| RPSL, Royal Philatelic Society (Prüferkommission) |
Attest |
Stanley Gibbons |
51 |
| CEM, Comision de Expertos de Madrid (Prüferkommission) |
Attest |
Edifil |
51 |
| BPA, Expertising Limited (Prüferkommission) |
Attest |
Stanley Gibbons |
51 d |
| The Philatelic Foundation, (Prüferkommission) |
Attest |
Scott |
51 L 1 |
| BPA, Expertising Limited (Prüferkommission) |
Attest |
Stanley Gibbons |
51,275 |
| The Philatelic Foundation, (Prüferkommission) |
Attest |
Stanley Gibbons |
52 |
| The Philatelic Foundation, (Prüferkommission) |
Attest |
Stanley Gibbons |
52 |
