Nothing like using Armstrong (who makes lanterns and holder to this day)
tool holder to cut plastic and stuff that needs a sharp edge.

IIRC, Armstrong sells direct themselves.

http://www.armstrongtools.com/ECommerce/Category.aspx
and scroll down the left navigation to "workholding" (yes, I know it's
toolholding, but that seems to be where they've lumped it in).

I seem to recall paging through an Allen Tool catalog that listed a
bunch of this style toolholder as well, but in searching for them, I
found they were part of the Danaher group along with Armstrong, so I
guess that comes as no surprise.

--Glenn Lyford