As far as the 169 is concerned, even several years prior to 1971, I reckon you'd have been lucky to find one, given that Court found just 1 in 846 of the 1909 pennies to be F169 (0.12%). So even if you'd changed £100 into pennies (240 x 100 = 24,000), the chances of you finding a F169 amongst them, would still have been slim, given that there probably wouldn't have been more than what.......100 pennies dated 1909 amongst the 24,000.
Incidentally, Freeman was correct, the rock above Britannia's foot is a different shape to reverse D, although personally I can't see any obvious differences with the waves and the exergue. However, on mine at least, the sea to the left of Britannia, under high magnification, doesn't appear to reach the linear circle. But it does on my 1910, which is also reverse E. So maybe an optical illusion or wear.