SENEGAL (1965) Dakar post office. Trial color proofs in strip of 5. Scott No 246, Yvert No 251.
AVAILABLE AT $65
FRANCE (1973) Postal museum*. Trial color proof strip of 3. Scott No 1389, Yvert No 1782.
AVAILABLE AT $30
RWANDA (1986) Hand cancelling stamp*. Set of 3 progressive proofs including final colors. Scott No 1246.
AVAILABLE AT $25