I'll try to help
what are you considering north central??? I know a guy in Warsaw that would probably do it, and he does good work. Also know a guy south of Kokomo that does excellent work but he's way behind. Shop in Warsaw is Timberwolf. Owner's husband is city cop and does work on the side.
There's also a guy in South Bend that manufacturers 50 cals, so it'd probably be pretty easy for him. PM if you need more info. HTH