Odd Hallmark on Ebony Sterling Cufflinks

[Peganmn]

I've searched all over for a clue about this hallmark. I assume it is a hallmark as it is on both cufflinks at the same spot. It looks as if someone took a round punch and just punched a series of dots in a roughly flower shape, and there's a sterling stamp on the other side of the link. As you can see the hallmark is not exactly the same on each link. My best guess is that they're mid-century American, but I've yet to find a mark anything like that. The wood appears to be hand shaped ebony. The swivel mechanism is a common one and has a patent number that dates them at least after 1949. Any help or thoughts appreciated.
http://i603.photobucket.com/albums/tt11 ... 78d2df.jpg
http://i603.photobucket.com/albums/tt11 ... a1dd01.jpg

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