SWMBO has a pair of antique folding scissors. The main joint between the two
halves is held with a screw and therefore is easy to adjust.

But each half has a hinge-joint in the middle, to allow the folding action;
these joints are not easily adjustable (no screw head). Each hinge-joint is
very simple, one piece of metal is sandwiched between 'prongs' in another
piece. There is a rather blurry photo to show this:
http://s409.photobucket.com/albums/p...t=scissors.jpg.
Some sort of rivet (or screw?) passes through to hold it together.

On one face, the end of the rivet (or screw?) is visible, but filed/polished
flat with the surrounding metal; on the opposite face there is nothing -
just continuous plain metal with no evidence of the rivet (or screw) end.

The hinge-joints need to be quite tight to allow the scissors to be used
easily, but one joint is very loose.

Is anyone familiar with this construction - can you suggest the best way to
tighten the hinge-joint without damage?

Cheers