Unfortunately its not a standard clevis pin. Looks like a custom version made for MSR. The head relative to the shaft diameter is not much bigger than the shaft. A bolt may work temporary but in that size its going to be fully threaded. Thread on a pivot point is a bad thing as its going to chew up the holes that the pivots ride on. There is not a lot of "meat" on the pivot plates so not good to screw up the holes. Might get me home but may damage the entire snowshoe. The ring is a smaller diameter than the ones I have seen. A standard split pin will not fit in the space given.
Good point about a threaded bolt chewing up the pivot plate and/or bracket.
The rest of your post made me think that it might not be the worst idea in the world for my first time doing this repair to not be in the woods with cold fingers, so I brought a shoe onto the kitchen table, fished my ditty bag out of the pack and tried to do the repair with what I had in the bag. When I got the shoes and looked at the pins, I just eyeballed the size of the pin and threw into my bag a pin that I figured would fit. Turned out, it *did* fit fine, albeit a bit longer than I'd prefer, but I still think it would work, and it didn't take long to do.
But I looked at the hole in the original pin, and I'm still convinced that a cotter pin will work fine, and might be the most durable way to secure the end of the clevis pin. I used a paper clip, probably not the most stout material, but it went on easy as pie. I also found a small nail, and had no problem using it to secure the end of the clevis pin. Just would use the needle nose pliers on my Leatherman tool to bend the end of the nail to keep it from slipping out. Maybe a safety pin might do the job in a pinch.
Here is a photo showing the original pin on the right, my repaired pin with a paper clip on the left, and in the middle of the picture, below the bracket, is the original pin with a nail through the hole in the pin (but not bent around)
But whatever you figure to use, try it at home first to make sure it will serve...
Was wondering about the failure mode though. Seems like the clevis pin, bracket, and pivot plate are all pretty stout, so is the weak point the split ring that secures the end of the clevis pin? The only thing I could think of is something somehow latching onto the ring and pulling it apart, the clevis pin falls out, and the binding comes loose. Do both pins tend to come loose and the whole pivot plate seperates from the bracket? I'd think that one would fail at a time, rather than both... Curious to hear from folks that had failures what the failure mode was...