Those aren't Honda bag rails so anything stock may not work. The stock rails have a spacer that is about an inch long and needs a long bolt to tighten up.
The best bet is, like mentioned, Ace Hardware!
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Bag rails are definitely not stock, but they attach to the OEM bag guard at their front attachment. So missing bolt is for front bag guard attachment, not the bag rails. Pretty sure bag guard is OEM so I did order a couple of #35 bolts. Will not be shipped until after Memorial Day, so Ace should hold me until they arrive. thanks.