Here are some thoughts -
The first few leather/kydex combos I did used a stack of a stainless acorn nut, a SS washer, the kydex/leather, then another washer and a stainless machine screw on the back to affix the paddle, in addition to eyelets on the rest of the sheath. That was ridiculous and I had to locktite everything. I recently changed to the "binding post" or sexbolt as the machine catalog calls them for all the connections, I figure it's basically a chicago screw with a drive socket or slot on both ends and the ones I obtained appear identical what I see in your picture. Running those through the open center of the eyelet/grommet sounds like an excellent idea. The binding posts are $0.90 each in galvanized and $2.60 in SS so I try to keep the usage of them to a minimum. Running both would allow a few less binding posts and the essential kydex fixture to be accomplished mostly with the less expensive eyelets.