The stocks weren't always numbered. I recently obtained a .38 Double Action / 5th Model, and neither the barrel or stocks were numbered, although both were obviously original to the gun.
With age, those black hard rubber stocks often turn brown. Sometimes soaking them in mineral oil will turn them black again. You can obtain identical modern replacements from: www.e-gunparts.com
I think what you are seeing on the revolvers interior may be a combination of black powder fouling and dried grease. It could also include some traces of Carbona or Charcoal Blue. Try scrubbing it off in a bath of carborator or brake cleaner, but be sure to oil everything down afterwards or it will rust. Also wear rubber gloves. Bore solvent is designed to desolve lead, copper and sometimes nickel. It generally won't touch the gunk found in the interior of 19th and early 20th century guns.
With age, those black hard rubber stocks often turn brown. Sometimes soaking them in mineral oil will turn them black again. You can obtain identical modern replacements from: www.e-gunparts.com
I think what you are seeing on the revolvers interior may be a combination of black powder fouling and dried grease. It could also include some traces of Carbona or Charcoal Blue. Try scrubbing it off in a bath of carborator or brake cleaner, but be sure to oil everything down afterwards or it will rust. Also wear rubber gloves. Bore solvent is designed to desolve lead, copper and sometimes nickel. It generally won't touch the gunk found in the interior of 19th and early 20th century guns.