Thanks for your feedback. Yes, The PCI-01B does indeed fit in the D600 case. Just for future record, the PCI-01B fits in all our cases except our small form factor ones. The installation of the PCI-01B is simple enough, and the instructions are in the packing. You shouldn't have a problem, but let me know if you do.
Also, we have recently increased the threads of the screw holes as you can see in the image below.