Most probably François Garnier (d. 1774).
The intriguing 'FG' stamp, which appears mainly on a group of early Louis XV commodes, was already discussed by the Comte de Salverte and Jean Nicolay. To date the ébéniste who used this stamp remains not clearly identified, although it has often been suggested that it may be associated with François Garnier, father of the celebrated Pierre Garnier (maître in 1742), and established in Faubourg Saint Antoine. A Louis XV ormolu-mounted kingwood and parquetry bureau plat stamped 'FG' was sold Christie's London, 12 June 1997, lot 110, while a kingwood commode bearing this stamp, and formerly in the collection of the duc de Trévise, is mentioned in F. De Salverte, Les ébénistes de XVIIIe Siècle, Paris, 1953 (4th ed.), p. 320.