Books and professional appraisers.
Go to the library and look for Flayderman's Antique American Firearms. You should be able to identify your pistol from the pictures and descriptions in the Stevens chapter.
No. An antique bullet is 100 years old. That is the meaning of "antique". But they can make modern bullets to fit and antique pistol.
Markings
check the dates on them
wrap it, box it, go to the post office.
$800.00
the people who evaluate antique guns have a refence guide/book they use. they also need the gun 'in hand' to note the condition for themselves. based on their findings, they can attach a value to an antique piece..........in a lesser way, you, too, can evalute an antique pistol by securing an antique gun book and compare your pistol to the condition they list. buy a copy of "bluebook of gun values" thru Yahoo or your book store.
More information is needed to identify the manufacturer of this pistol.
It's an unique pistol & antique as well depends on demand as it could be 500 USD till 1000 USD
Take this to a reputable antique dealer
Depending on EXACTLY what you have; 100-1000 USD
What are the markings on the pistol?