I got the heatsink part from the framework store along with 3 spare ptm pads for the die-side.
PTM pad from LTT (for the shim/heatsink side): PTM7950 Phase Change Thermal Pad – LTTStore
Copper Shim from Amazon: Amazon.com: Copper Pad Shim Thermal Assortment Kit, IC Chipset GPU CPU Thermal Heatsink Copper Pad Shim 20 x 20 x 0.8mm, Pack of 20 : Electronics
And some higher grit sandpaper that goes higher than what I already have: High Precision Polishing Sanding Wet/Dry Abrasive Sandpaper Sheets -Grit 3000 5000 7000 Germany - Amazon.com