All About Pocket Knives

I am just wondering how Sport Colbs has this Case Tested 6231 listed with Delrin scales. Nice knife, but if I'm not mistaken, DuPont didn't start making Delrin until 1960 at the earliest and I think Case didn't start using it until about 1967?

https://www.ebay.com/itm/Vintage-Case-T ... Sw7Dtc4p-T

The knife is fine. Jigged black composition handles. Military WWII. He is calling it delrin but it is not delrin. But the knife is 100% authentic.

Thanks Steve. I was mostly wondering if it had been rehandled. As always I appreciate your expert opinion.