Welcome to tfl!
You might consider asking in the Curio & Relic subforum.
Read the rules and only post your questions in one forum, for instance don't ask about the something in Rifles and then ask the same thing in Handloading...
Pick one and ask, duplicates in other forums will be closed.
General is fine, for general things, and can get you pointed in the right direction for more specific answers.
Most important is the information about the gun. Make, model, caliber, and everything written on it. Pictures are good but not as immediately important as the data on the gun itself.
The .38 WCF (Winchester Center Fire) is today usually called the .38-40 and first appeared in the Winchester 1873 rifle. A few years after that Colt put it in their Single Action Army pistol (aka the Peacemaker).
The ".38" in the name is a misnomer, it actually uses .40 caliber bullets, and the "40" refers to the original loading of 40grains of black powder.
.38 WCF or .38-40 has been chambered in a lot of guns since it was introduced, including several Winchester rifles. To be of more help we need to know which rifle you have. it's marked on the rifle, either the model year or the last two digits of the model year depending on when it was made. Older guns often have the entire date, for example 1894 while newer ones may only say Model 94...
Starr was one of the gunmakers who's pistols were used by the Confederacy during the Civil War, I'm far from expert about them, I think one model was a double action...
You can get a lot of information just by using Wikipedia, not all of the info there is correct or accurate but most is, and its an easy place to start.
Welcome to TFL!