500-1000
18 inch barrell 1863
Value is more determined on condition. The length of barrell and serial number are helpful but the Model of the revolver is essential. Without knowing the model number the question is almost impossible to answer honestly.
Around $600, depending on model and condition.
Ruger would be your best source
Long
Depending on condition, between $175-$275.
You can request a owner's manual at the Ruger website.
I know smith and Wesson sells them and maybe ruger. not so sure on ruger
150 USD
Ruger will tell you over the phone. If you can access the Ruger webiste, the data you want is also there.
A call to Ruger will get you the answer.
Go to gunbroker.com and look under Ruger.. It will give you a ball park...