27樓這一封集票(撇幣)、郵資首日和少見收件地等特色，確是貨真價實不可多得。

There was a seller who sold about 10 to 15 covers sent from Taiwan to Bank of China in Havana Cuba  two years ago. Most of them were flying geese covers. I only managed to acquire the first cover he sold since it was relatively inexpensive. (See link below. No. 14 posting). The rest of the covers were too expensive for me to acquire.

http://chch.idv.tw/phpwind/read-htm-tid-23310-fpage-0-page-2.html

It is possible that someone in the bank kept most of the covers till they closed the bank.