That’s a great question. It looks to me like they are following the original design. They are pretty proud of the fact it’s American made and they showcase the patent number. I’d say it’s legit. A guy could contact the seller through eBay and ask him that question.
There’s also another seller that is selling what appears to be new old stock. At least it has the older style label on the inside. Then there are some other ones on there that are obvious Chinese knock offs. It’s a jungle out there! Lol