You can also go the double-negative route. Contact or enlarge onto an appropriate black and white film
to generate and interpositive (with appropriate filtration to null out the effect of the orange mask),
then onto a second sheet of black and white film to generate your actual printing neg. This route has
certain significant advantages in terms of tone or grain control, plus you can apply supplementary filtration to balance the scene just like in the field.
As an aside, I saw Panalure on the shelf of our photography store here just last week. No prices, but the boxes were very old. The Kodabrome II next to it, equally old, was $269 for 250 8x10 sheets.
Warning: Yes Panalure was truly a great paper. But...you cannot believe how short its life was. It did not age like other B&W papers. About 15 years ago I bought a box of 250 sheets (8X10) at a camera show and I immediately tested it. It was perfect with truly white whites. Then I put it away (at room temp) and only two years later I tested it again: almost total fog. This paper age-fogs rapidly so be warned about buying it now! - David Lyga
Agx: yes, and you have to make sure your copy film is pan. If it's ortho or blue-sensitive, it will be largely blind to selective filtration, and that orange mask will equate to neutral density. There are a
few tricks to this, but once learned, it's easy enough.