When dear old King George V exhaled his final breath, the attending Doctor turned to that little Nazi maggot and said, "Your Majesty, your father is dead."
The Monarchy transfers at the instant of demise of the preceding Monarch. You have a similar thing in your country, John: LBJ became the ACTING President, fulfilling his duty as Vice-President, at the instant that JFK was hit and he became the President at the instant that JFK finally died. The Supreme Court Justice simply administered the Presidential Oath aboard Air Force 1 as required by the Constitution. America is NEVER without a President, England is NEVER without a Monarch. The Coronation simply is when the incoming Monarch takes the Oaths required by Kingship: to God, to the Church, to the Nobles, to the Free People. They don't take an oath to the esnes any more because somebody made a law against buying Englishmen. They are all supposed to be Free Men now, but you would never know it by the Inland Revenue (same as IRS or Revenue Canada)!
RFI is Rifle Factory Ishapore. It is often done in a fancy style with the "I" lowered slightly just in case they decide to add a few dozen more rifle factories. If they added one at Bangalore,for example, it would be Rifle Factory Bangalore and likely would be listed as RFB and monogrammed as RF with the B below or above and a Broad Arrow in there somewhere. But the Raj is gone (more's the pity, what) and we are all 'democratic' these days, so the Arrow would be out the window, definitely. A new stamp would be based on the capital of the Tower of Ashoka, which they spell Asoka with the dot that my keyboard can't make.
Same thing, you often will find parts stamped "IS" on reworks; this, again, is Ishapore which is now called Isapur wth a dot over the 's'. My keyboard isn't worth BEANS at transcribing Hindi! Or Polski. Or Romanian, for that matter. Bad enough on English: no "Ae", no Thorn, no Edh, no "Yt"..... and I need them all for a book I am working on!
Sorry I can't help on the "F". Possibly a personal comment from an Inspector, but I rather doubt it! It definitely appears to have been applied at the time of a rework, though: nice, clear stamp, well struck and has not been buffed away, as the original date stamp.
Hope this helps a bit.
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