Thank you all for your response! I don't know if it's that deep, after I tried to super glue it I sanded the super glue so that might have led to the color changes in the crack. I haven't tried neetsfoot oil even though I just bought it for my other shell boots...At this level of cracking, you may be able to use neetsfoot oil to moisturize it so much the cracking won't continue.
It seems like it is just some cracking along the very top edge of the shell. Can you take a much more zoomed in picture?
My one shell LWB that cracked had -deep fissures- where you could see the yellow inside of the shell through the black dyed outer part. This doesn't seem to be that.
Do you guys think that maybe some sanding of the shell could work here? If the crack is as superficial as I think, you could possibly sand that layer off entirely. @friendlygoz haven't you sanded down your shell shoes before? What do you think of that possibility?
Jay, you might also want to call up Horween tannery and speak with someone about your shell issue. I actually spoke with Mr. Horween himself and he was 100% willing to help me out, but told me that my LWBs were impossible to fix given his knowledge of cordovan (which is probably the best in the world).