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What are the odds of finding one?
There are 120,960 such numbers, out of 100 million total possible numbers, which comes out to one such note in 826.7 (assuming 0-7, 1-8 and 2-9 are all allowable ranges but no others are allowed).
That said, in modern series, notes numbered from 96000000 up aren't supposed to circulate; there are 2160 "jumbled ladder" numbers in this range, so the rest has 118,800 out of 96 million (which is to say, approximately one in 808).
For comparison, this is (slightly over) 12 times more common than a radar (ABCDDCBA) or than a four-digit repeater (ABCDABCD), and (very close to) 3 times less common than a note one wrong digit away from a radar (or, equivalently, from a four-digit repeater).