The blade is marked 'I.SALTER',  this is John Salter ^[2],  35 Strand, London, noted between 1800-23.  Blade also marked with BO inspection mark of 'Crown' over '19'.  The 'G.F' stamp is unknown,  but it may be a son of Samuel Galton a Birmingham maker.

The blade shoulders are of India pattern type.

 

(1) The Brown Bess Bayonet 1720-1860 by Graham Priest, page 102 & fig.84, ISBN 0-946696-05-5

(2) The Brown Bess Bayonet 1720-1860 by Graham Priest, page 150 , ISBN 0-946696-05-5