The 2023 Summer Auction - Sale 340 Day 4

1860s-80s a group of 3 Hong Kong QV used stamps with Forged postmarks,including D30, Y1 & Kiung-Chow obliteration. The bluish Y1 applied on QV Wmk CC 96c Olive Bistre was firstly obtained a 2007 BPA cert stating that it is genuine, however it got another 2015 BPA cert stating that the Y1 obliteration was forged. An interesting lot, good for reference.