There are recorded several people by the name of James Dixon in Sheffield. One is recorded as James Dixon of Campo-lane, (in the centre of Sheffield an old lane behind the Church) in a list of Common Pocket and Penknives - Manufacturers in Sheffield; he is also listed at that address as a Cutler. Is this the correct James - (in the sense of this being the James Dixon's father?) - and if so his mark is also listed ( 'Dixon' below a + sign).
To confuse matters another James Dixon is listed at the same time as a Joiners tool maker - his address is Silver Street which is of course where Dixon and Smith were later located.