I was looking over Kelleher's upcoming August 11-12 auction catalog and noticed something interesting. Some collector/dealer seemed to have an obsession over the US C46 80c Diamondhead airmail stamp. Lots 1059-1063+1066 contain a total of 10,863 plate blocks of this single stamp. The total production of this stamp was 18,876,800. Divide that by 50 and the maximum total number of plate blocks for this issue is 377,536. This accumulation represents 2.87% of all the C46 plate block that could possibly exist. Since many plate blocks would not have been saved, the actual percentage of all the surviving C46 plate blocks this accumulation represents is much higher.
To top it off, Lots 1070-1072 contain 280 full sheets of C46, I assume from the same hoard.
Were they trying to the corner the market in hopes of driving up the price of their huge stockpile? That is the best guess I have.
It makes you wonder what other huge stamp accumulations are hidden away...
https://stampauctionnetwork.com//V/v8512.cfm#10