Impossible to answer. Only Colt knows.
Information not in the public domain.
You want to ask "What was considered 'The Peacemaker'", which was the 1873 Colt Single Action Army revolver, generally in .45 Colt caliber although it was produced in many different chamberings.
The Colt Peacemaker (one of many names it was given) was one of the Single-Action Army (SAA) Colt revolvers. Production of the Colt SAA revolvers started in 1873, and ran through three generations of production. One Ended in World War Two. The last generation of Colt SAA started in 1974, and has not officially ended. With the popularity of the Colt revolver, especially with growing membership in shooting clubs like SASS (Single-Action Shooters Society), demand for the SAA is still strong, and they are still being produced.
Many have, primarily Colt.
I'm pretty sure you mean the Colt Single Action Army or Peacemaker on the civilian market. Colt made a version of this gun with a 4 1/2 inch barrel, this was the "gunslinger" model. A new Peacemaker goes for about $1,300. You'd have to talk to a gun dealer or collector to find the value of yours. Age could work in your favor for resale. But age, how well it's been kept, how many bullets you've put through it will affect your price.
One of many models made by Colt
Only Colt knows
600
@9,500
No one but Colt knows and they aren't telling.
Yes, but there is many copies made throughout the world.
Only Colt knows, and they might not even know to the last one.