These Cinderellas are called Flight Distress Stamps. Not really conclusive that they had any charity angle. May have copied Nowegian stamps produced to fund Arctic exploration
1925
Alaska Mercy Flight 10
Alaska Mercy Flight 6
Alaska Mercy Flight 7
Alaska Mercy Flight 8
Alaska Mercy Flight 9
Mercy Flight 1
Mercy Flight 2
Mercy Flight 3
Mercy Flight 4
Mercy Flight 5
Mercy Flight 7
Mercy Flight 8