I have a Thermaltake Water 3.0, I upgraded my PC and went from an AMD CPU, to an Intel CPU, but I had lost the Intel mounting parts.
I based my design off this: https://www.thingiverse.com/thing:3145622
It fit perfectly around my Thermaltake cooling block and the CPU mounts in the motherboard but I could not use it to hold it in place. So I created the extra edge that lies on top of the "pins" around the block and created the hole for the cables to escape.
My original design and print had slightly too large of an inner edge that I just carved down with an exacto knife, I provided the original STL that I printed and had to carve down and an edit where I have made it smaller (but have not tested)
I decided to maintain the 3mm mounting holes on both models even though I used 4mm mounting screws myself, if you want to use 4mm mounting screws you can either drill out larger holes or just edit the STL
I was going to use the original design I based this off as a mounting plate for the back but it didn't fit, I ended up just cutting it up and using the pads off it for mounting. I was feeling a little lazy and didn't bother with making a proper backplate for it
Little bit of smoothing with sandpaper and making sure the holes accept your screws