Hi Rebecca.......welcome to TFF.
You're absolutey correct.
What you have is a French Model 1873 Ordnance Revolver. These were used by the French Navy for it's NCOs from 1874 until 1945. They were built by the French military armory at St. Etienne between 1873 and 1886 and approx. 350,000 were produced.
According to The Standard Catalog of Military Firearms, it's value is:
Exc. - $400
V.G. - $300
Good - $200
Fair - $100
If everything works properly, I'd judge yours to be in the "Good" category.