India used in Persian Gulf – “MOHAMMERAH” cds on 1921 GV cover to Liverpool

India used in Straits Settlements – 1854 4a blue and red 4th printing, Head Die III, Frame Die II, horizontal pair pos.14/15, wmk reverse, showing center guideline on top, cancelled with “B/172” of Singapore, scissor cut at top between impressions. SG Z67. £6,500 as singles + premium for a pair. A major rarity! – 2019 BPA certificate states that cancel is indistinct though one can clearly make out it is “B/172”