....three years ago I sold these two : almost $100 for the Averill and about $70 for the Gelbert.....because of their age and fragility and being over-sized ( and the big blank backs were an invitation to artists and stats-keepers ) anything over a ''5'' has very low population .
...tilt them into a strong light to check for hairline wrinkles ; I have a lot of these in what looks like NM but they come back as 4's. Good luck with them..