It just so happens that I saw a butterfly leaf table in Costco not more than a week ago. It was part of a dining room table set which they had for sale. This was a regular Costco, not the furniture store nor Costco.com. Suggest you go and look at them in detail. (Take your guessing stick and a note pad. LOL)
The whole secret of those critters is in the hinge. If you can find a source for the hinge you'll have it made. If you can't you are SOL. So look both for any indication of who made the hinge and who made the table. Then you'll have to go on an internet search for the companies and a source for the hinges.
I have a very long and involved story, complete with photos, about rebuilding one of those critters which was built in the 1930s. It is now my daughter's dining room table. If you are interested, drop me an e-mail and I'll tell you a little about it. (It was once part of the subject of a 'thread' on these forums. But most everything disappeared in the meltdown last June. Wish I'd kept a copy.) My e-mail address is: email@example.com
Bob Hoyer ......