UPDATE:
Well I went down to my trailer this weekend and measured the distance between the two leaf bolts. I bought a 26.250" leaf spring and the bolt distance measured exactly...26.250". So THAT was not the issue.
So I emailed the trailer part supply company over the weekend with pictures and received a reply this morning. Effectively, the email said something like "I spoke to my lead technician and he says there is no way that leaf spring can come off...etc etc".
Well of course I had to follow this up with a phone call. I asked for clarification and after his explanation, I kind of ended up getting one of those "Gee I'm actually kind of stupid for even asking this question" feelings.
He very politely explained that since all of the weight is bearing DOWN on to the leaf spring, it can never come off. At this point it still didn't click for me. Then he said the magic sentence: That little hook part AT THE TOP isn't actually even doing anything. Then it clicked. Imagine the spring is entirely missing the little hook part. If the trailer is bearing DOWN, the spring will flatten and the whole spring will actually get even longer. Since the weight is bearing down ON TOP of the spring and the U bolts are holding it perfectly in line with the bracket, it's just going to flatten out momentarily and return to it's original position.
Also of note is that this particular wheel is probably at its "extreme" position. The equalizer will probably balance things out when I'm moving forward. (I'm just assuming this as this subject wasn't discussed with the trailer people).
Anyway, just wanted to update because I know I'm not the only person with this issue and won't be the last person to ask this question. Hats off to Pacific Trailers in Chino CA for helping me out with this one. And thanks for everyone's helpful comments in the Forum.