Nothing unusual about bifurcated rivets, still in common use, available from Bunnings as well as numerous other suppliers.
https://www.bunnings.com.au/pinnacle-12-5-x-4mm-nickel-bifurcated-rivets-20-pack_p2460051
Nothing unusual about bifurcated rivets, still in common use, available from Bunnings as well as numerous other suppliers.
https://www.bunnings.com.au/pinnacle-12-5-x-4mm-nickel-bifurcated-rivets-20-pack_p2460051