but MY code has systematically shifted these down by 1.
This error results from my faulty recollection of what was actually being done by some code that I wrote a couple of years ago, so when I entered the parameters for the new intervals (those above), the code generated 23-26 for length interval 1 instead of 24-27, etc.
So as I said, I will rerun everything. Very sorry for the delay, aggravation, and the work you've already done on the data you've already been sent. I hope you're still willing to work with me, given this unfortunate circumstance.