Likewise, a Wilkinson gun is marked "Wilkinson, No. 27 , Patent, 1866. I cannot find that one in the volumes of Abridged British gun patents. This gun does have the lever forend.
Well then, it appears we are still in patent attribute fantasy land but I would assume the "No. 27"( of Pall Mall) a component of the address being the same as Charles Harvey. I have found a document of the 1886 patent listing:
http://books.google.com/books?id=BWsyAQAAIAAJ&pg=PA95&dq=william+wilkinson+%26+son+british+patent+of+1866&hl=en&sa=X&ei=17qOT6aNOYWa8gTxg-2gDg&sqi=2&ved=0CEgQ6AEwAg#v=onepage&q=william%20wilkinson%20%26%20son%20british%20patent%20of%201866&f=false
So getting back to 1st principles, Sometime prior to 1853 accomplished swordsman John Latham was taken into the Wilkinson & Son fold as he married one of the daughters of Henry Wilkinson, son of James Wilkinson who was the son-in-law of Henry Nock. In December of 1853 a document was penned detailing an agreement for the transfer of the company to John Latham. Henry Wilkinson's retirement may have been in 1858 followed by his demise in 1861 due to cancer. John Latham looks to have been an excellent manager and under his direction the thrust seems to have been along the lines of edged weapons. Also the 1860s look to have some drama to the agreement and subsequent takeover which seems to veil any improvements in breech loaders.
Note too that John Rigby moves to London in 1865/1866. Anyone hazard a guess of the date of the 1st Rigby with the grip catch?
Kind Regards,
Raimey
rse
