Yes, the rear bracket is actually a separate HPE SKU. Here's the SKU's as far as I've been able to tell:One thing I noticed on mine is that the M.2 retaining screws appear to be part of the heat sink retainer assembly. Without the heat sink, there's no way to actually keep M.2s in place. It should be easy enough to draw up a part and 3D print it.
Awesome works Scott! I'm going to try to print on my end, see how I go. I picked up one of these and subsequently another 3 more recently. Looking forward to see how you go with the heatsinks as well.I'm working on getting a few sample heatsinks, but that'll probably take 2-3 weeks.