It looks like this is a bad scan of a photocopy original, plus it also looks like the two figures have been cut out and placed onto a make shift background. The results wont be any better than what you have from the restorers who have already submitted valiant efforts.
There is just nothing to work with, in truth it would be easier to pick up a pencil and paper and draw an impression of what one might think the features are of these people in the picture.
Its close to mission impossible without 100% re-invention (drawing).