I found the photo of how I trimmed the 100mm skewer bolt so that it wouldn't stick out on the other end on my 74mm dropout. I had forgotten to thread on a M5 nut before cutting (for cleaning up the threads from the inside), but the cut was so clean that it didn't matter. The brown disk at the bottom is what I used to cut the steel. Using a clamp and a drill stand made it much easier and a cleaner cut. There were a few threads remaining when screwing it into the hub and dropout, before bottoming out. Not all 100mm skewers have such a large amount of thread length though, so you'd have to check if the one you get would work.