First it would help if you could post some pictures of the revolver from a few different angles. This will help members here in identifying exactly what it is you have inherited from your wifeís grandfather. Then depending on the condition and what custom features it has you can determine a value for the piece. As far as contacting potential buyers, there are a few gun related auction sites that could assist you with that as well.
NRA Life Member
"Democracy is two wolves and one lamb voting what to have for lunch. Liberty is a well armed lamb contesting the vote" Ben Franklin
"The constitutions of most of our States assert that all power is inherent in the people; that... it is their right and duty to be at all times armed." --Thomas Jefferson to John Cartwright, 1824. ME 16:45
"It is Godís job to judge and forgive my enemy, I only arrange the meeting." Unidentified Marine