Details of a stamp in my main collection

CID1
StampRef3527
SetRef0
CStateUS
ItemID15297
CoverID
Qualitygood
DescriptionHuge lower margin, top margin appears to be torn, just touching design. Part dotted Chinese cds with Shandong in top section.
CollectTypeMain Stamp
CommentVertical perfs visible on both sides. Unknown previously AFAIK. Mizuhara ssys that multiples have never been found, but these, probably unofficial, perfs imply that the stamp was from the bottom margin of a sheet.
Location10
Multiplicity1
PurchaseID3948
PricePaid255.55
CurrencyGBP
Accession20240524
Disposed

There is one example of this stamp in the collection.