RM over EH into a lozenge 

Richard Martin & Ebenezer Hall -Martin, Hall & Co- ,

The origin of the firm in the partnership established in 1820 in Sheffield by Henry Wilkinson and John Roberts who traded as Wilkinson & Roberts.The firm's cronology is: John Roberts (1836), Roberts & Hall ( 1846), Martin Hall & Co (1854), Martin Hall & Co Ltd (1866-1936). Martin Hall & Co was one of the best known British manufacturers and partecipated to many international exhibitions including the Crystal Palace 1851 Great Exhibition. They had also a line of production in electroplate and in a patented white metal called "Martinoid"

Sheffield 1905 hallmark

London 1883 hallmark