It could be commercially made.
the right hand left hand thread systems are and were used on some auto body files for flexing the files.
The rivets look cleanly peened.
Bent rod like that was a standard method for manufacturing mini hacksaws( and still is) as well as for manufacturing coping saws.
Also, there’s another one listed on Etsy.
Find the perfect handmade gift, vintage & on-trend clothes, unique jewelry, and more… lots more.
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The listing doesn't list a manufacturer either.
Also another listed on eBay.
We hope this doesn't cause you any inconvenience. Great PIECE of a BY-GONE ERA.
www.ebay.com