No philatelist, not even in the 1930s, would treat a rare stamp the way the Chinese Mandarin was treated in this film. Touching the stamp with bare hands, keeping it loose in a folded up piece of paper, licking and posting a stamp, etc. While "hinges" (tiny bits of sticky paper) could be used by everyday collectors to attach a stamp to a book or display case in this era, elite collectors still would have been loathe to ruin a stamp so rare.