The estimated value of $20K seems low, unless it's in poor condition and/or there are many other copies around. Google says the same auction house sold one for

The estimated value of $20K seems low, unless it's in poor condition and/or there are many other copies around. Google says the same auction house sold one for $100K in 2012: https://www.reuters.com/article/idUSBRE8AT04H/ https://www.reuters.com/article/idUSBRE8AT04H/