Please forgive the presumption, but it looks like the older pruners could be rejuvenated significantly with some fine sandpaper, or Comet cleanser followed by a sharpening stone on the edges.
f you don't have a sharpening stone, you can glue fine sandpaper (400, 600 or 800 grit) to a wood block or tile or anything flat and stiff. Basically, make your own fine-grit Emory board.
You might not be able to get a flat sharpening stone onto both edges of the inward-curved jaw. Wrapping fine sandpaper around a finger and stroking very gently can sharpen an inner curve (or amputate the finger - YMMV).
