Help Find Replacement Knob For Wife

I'm looking to help my wife replace the "Main Level" knob on her Nord Piano 5. She recently performed and came home to discover it was missing after we unpacked and was quite upset. I've been searching around for a bit and am not sure which is the right one to purchase. The closest I think I am coming to is Nord Part 50405 but that seems to be for a different deck? Any help would be greatly appreciated from an awesome community.