Welcome to the forums from the Wiregrass! You might try this site
Heritage Gun Books - Gunsmithing, Repair and Maintenance Manuals (or Amazon) for books written by Jerry Kuhnhausen specifically for the S&W revolvers. Keep in mind that the Model 1902 had several engineering changes to the trigger return and hammer rebound functions. Your gun does not have a rebound slide like modern S&W's and, instead, those functions operate differently than later guns. Parts are hard to come by...especially the trigger return spring.
You might Google "Ed's Red Gun Bore Cleaner" for a recipe for making your own CLP. It contains acetone and auto trans fluid both of which will penetrate varnish, gum and old oil from these old guns. It is also substantially cheaper to make than buying commercial cleaners.
Why not post some pictures? We love to covet old guns.