Blue Book of Gun Values
Have you tried a web search? Local Library? Do a web search on Harrington and Richardson Books and you will find some sources.
100 or so
200 or so
$200
100-300 USD
NOT much difference. Shikari was made before 1986 - single shot, hinged breakopen "shotgun" style action, with single action exposed trigger - 1871 Buffalo rifle made after 1987 - same type of action and transfer bar safety system - both chambered for .45-70 Gov't Cartridge.
Yes
50-100 or so
$100
100-400 USD
25-125 USD or so
25-175 usd