Identify knife

[Gary D. Williams]

I have inherited a pre-civil war knife that I am trying to get information on. Any help will be appreciated.
Wade and Butcher, bone handle, folding knife with a "hawk-bill" blade.(Pruning blade???) The blade has "XEO" engraved. My grandfather gave it to me and he said that his grandfather was given the knife just prior to the civil war. I researched three collector's books and I contacted a local collector with out any luck.

 

[Roger Blake]

this is from the Knife Collectors Guide, this edition, Ritchie and Stewart. "Wade and Butcher- This firm being Sheffield, England established 1819, one of the older original Sheffield cutlery firms. They specialized more in razors and fixed-blade cutlery, but have produced pocket knives in limited over the many years past. These being rare and of excellent quality, they bring high collector prices today.
collectible rating: very high
Stamping and logo: (An arrow and cross)