Marlin used casehardened receivers for almost all their lever actions prior to WWII. But the 1893's with barrels marked, "For Black Powder" were sold as "Grade B" guns, and had blued receivers, with cased levers, hammers, buttplates, and forearm caps.
The .38-55 Ballard is a fantastic old caliber, and still in production today. You'll find two different case lengths, as Winchester produced a bunch of short brass, and others have followed that trend. It works in your gun, but the longer original length will work better. It's getting easier to find, and I believe Starline sells the longer brass.
Looks like a nice old Marlin and will make a great shooter with cast lead, and a load around 1250-1300 fps.