I can't get any 2SC1583's that are not fake in any reasonable quantities. I am bummed out but from here on out I will be using PMP4201's on an adapter PCB.
It's not a perfect replacement but gets you almost there. I will see if I can get that 10% back by changing some part values but it's where I am at right now.
Here is a soundcloud clip that I made that shows some of the main differences in sound.
I socketed the 1583 so I could swap out the part and keep it in the same x0xb0x. The filter tuning is a little off in the clip, next time I will try and match it better.