brand new it would be worth 750$.
With the brief description that you have supplied,I would say that you have a SMith and Wesson model of 1905 4th change revolver.
50-1000 usd
What model?
50-275 or so
50-500 usd
100-10000 USD depending on EXACTLY what you have.
Impossible to answer without a detailed description of all markings and features.
Engraved and nickel plated Smith Wesson Model 29
50-500 usd
You need the services of a gunsmith.
No such revolver made by S&W
50-1000 USD depending on if if left the factory this way.