Drs. William and Charles Mayo
56%
| Country: | United States of America |
|---|---|
| Issue: | Doctors Mayo Issue |
| Date: | 1964-09-11 |
| Print: | Recess |
| Perforation: | 10½ x 11 |
| Emission: | Commemorative |
| Format: | Stamp |
| Face Value: | 5 United States cent |
| Print run: | 123000000 |