Value can vary depending on a number of elements. They made standard configurations of guns, and offered special order features. Anything unusual adds to the value, most modifications tend to reduce value. Original condition generally adds, poorly done "clean ups" tend to reduce the value. A refinish generally drops the value considerably unless done by the factory, or a very good gunsmith. (The vast majority dont fit in this class) Percentage of original finish has a big influence on value.
It's hard to simply say "X model" is worth this much without knowing quite a lot more about the particular gun in question. It's also possible to get a factory letter stating any known characteristics of the gun, which can affect the value tremendounsly if it has any unsual or special order features. The Buffalo Bill Historical Center in Cody Wy has the factory records and can research and send a letter for a price ($40 or so?) if the gun shows reason to document it.
Good clear pics will help quite a lot in making the next step in figuring out what condition is or special features it may have, and get a start on determining a value.
"Far better it is to dare mighty things, to win glorious triumphs even though checkered by failure, than to rank with those poor spirits who neither enjoy nor suffer much because they live in the gray twilight that knows neither victory nor defeat." -Theodore Roosevelt-