Lloyd, the economics of 10 men/37 guns makes sense. Around this time Purdey the younger remarked that he could keep the factory open with 80 pairs ordered each year and his factory employed about 40 men.
The shops also provided maintenance,repairs,alterations and all sorts of great stuff for their clients to spend money on.
The stark increase in serial #s may have to do with Charles Ingram buying Dougall's Glasgow business in 1893.