Digital BW, The Print

Peter - is the print something you can shoot or scan again, or do you not have access to the original?

If you can re-do it, try shooting it from a greater distance and/or at a rotation of 15-45 degrees from level.  If you don't have a RAW file and access to software like Phocus or something similar that has an option to treat moire, I doubt that you will have much luck trying to improve the file.

Good luck - 
Stephen Petegorsky