the quote I gave above was (seemingly) Amy(Winkle)'s husband speaking. (I have trouble with extended dialogue like this, keeping track of who's who.)

here it is again, for those who didn't note it at the time:
""It was hard work, but between us, we talked her over, for we had heaps of good reasons on our side. There wasn't time to write and ask leave, but you all liked it, had consented to it by-and-by, and it was only `taking time by the fetlock', as my wife says.""

To Take time by the forelock, to be well beforehand in one's arrangements. In mythical symbolism and its perpetuations, time is always represented by an old man with a head bald behind, and a large lock of hair in front. To take time, therefore, by the forelock we must get well in front of him, for once past there is no recalling him. A very comical perversion of this expression I heard perpetrated by a man of considerable information but no education, who observed that he had always been accustomed to take time by the fetlock.
- A. Wallace, Popular Sayings Dissected (1895)
[this merely presages much of what's been said here]

if LMA actually perpetuated this perversion and if between 1869 and 1895 it became popularized to some extent, then we've got History by the fetlock (always assuming History is a Horse, which Time isn't).