I have one of those, purchased solely to impress and make a conversation piece in a dish for a party. Haven’t used it yet for a party yet, but it works! You have to put the boiled egg in while it’s still warm, and then chill it for awhile. Comes out square :-)
Your square egg maker is a rare glimpse into a different, simpler era, and could bring big bucks on eBay.
“New In Box”!