Unless the veneer is very badly damaged it would be better to replace the defective portions with new veneer; small places can be filled in with a mixture of equal parts of beeswax and resin; melt in an old iron spoon oi ladle and add a little dry colour - Venetian red for mahogany, and umber for walnut. Press in with a slip of wood, level off with a knife or chisel, and finally smooth down with glasspaper. The old veneer may be removed by heating a flat-iron and pressing it well against the veneer; the latter can then be readily prized up by means of a stout knife or chisel. The old glue can be removed with hot water and rag: the rough surface which is left must be planed up and glasspapered in order to leave a surface fit for polishing.