Applicable Condition
As with any project you approach it based on many factors.
The " 2" Brass Wire Wheel" recommendation is not open to "Sensational" evaluations of use with "ALL" applications. Suddenly, my specific recommendation for this "specific project" applies a New Model 3 target restoration? NO..... it doesn't!
Lets apply the exact recommendation I made based on the Exact condition of the Op's gun without any "sensationalism". It's rusty, it has zero finish, markings are soft and barely readable. At best it's a shooter. Parts have to be viable in order to represent a Parts gun. Unless we want to include "Shooter Parts"? From one shooter gun to another shooter gun?
That's my impression based on the Op's input. So, that's my approach to this project and my recommendation based on that specific evaluation. Again, this isn't a $40,000 Colt dragoon!
I also base every project evaluation on "Time" on any project. How much time am I going to spend on this project? Is this gun worth my time? How much actual "Time" do I want to spend on this project? Maybe $2 an hour for labor and time is Ok to some? but it doesn't interest me.
A Brass Wire Wheel approach saves a huge amount of time and will, if used correctly, greatly improve the appearance of the gun, stop the rust, and likely loosen the screws on the side plate that appear frozen to me.
The Op has received many applicable suggestions from the forum. It's up to him which he chooses to follow or not follow.
Murph