Old nails
were handmade, square and often had beaten heads and were
generally uneven in appearance; whilst modern nails (post circa
1880) are mass produced and uniform.

Look for a
blackened area of wood around corroded iron nails.

The
Cabinet Makers tools always leave clear clues as to the period
when the furniture was made.

For example, modern planes and Period
planes work differently and leave completely different scars,
likewise Period saw-marks are unevenly parallel compared to modern
saw-marks which are identically parallel or radial.

Early glue
was made from animal products ( including hide, bones and fish)
melted in a glue kettle and mixed with water. Over time the glue
dries and crystallizes. Importantly this glue is reversible and
therefore antique ‘friendly’, as opposed to modern PVC glue which
is neither. So look for signs of crystallized glue, also loose
joints can indicate that reversible glue was originally used.

Always
look for worn components in the right places, take your time to
check the piece carefully and look for signs of use on the base of
the feet, drawer runners, chair rail stretchers and any area of
potential wear.