After posting this thread, I went through several packets of unsorted NY precancels I had and came up with my own copy of the "BROOXLYN" error. Unforutnately, my copy is severely creased.
Nevertheless, I attempted to scan it in high resolution next to a normal "BROOKLYN" Type 61 precancel. The result is below. You can judge for yourself.

In my opinion, if you really look closely at the open space between the top of the "K" and "X" you can see a very subtle difference in the space which confirms that a different letter is shown.
What puzzles me is that if this is such a common "error" why is it not listed as such in the catalog of errors that warrehouse mentioned in an earlier post?