You really want the old parts? I am sure I have a bunch of that stuff boxed away somewhere. I know I have a crank, front and rear derailleurs but no shifters. I got a bunch of road bars, but maybe too light for gravel? Don't know nothing bout' gravel but they are slow bikes for kids who want to play in the dirt
Lemme look this weekend. Not sure exactly what you are looking for? I remeember my old Kore Mtb stem sitting around in my shop somewhere. Its brand new but not sure if it will fit your drop bar? if it fits, you can have it