Impressive work; kind of not surprised at the outcome... said with respect.
Next step... used version 2 motherboard transplant, and we've figured out what to look for on the right-hand side of the motherboard bar code label. There is a point when the 2-alphanumeric "REV" version changed for the v1 vs v2, and also specific HP part numbers to ensure you get a v2. Plus, you need to be very clear with the seller about what you need to get and why. Let them know you will require a refund if they send the v1 type instead of what they showed in their ad pics.
I used to say it took me 1/2 hour to do a motherboard transplant, but that was rushing. It really is about 1 hour from start to first boot.
Last, you generally never know if the Zx20 recycled motherboard you buy was "branded" for Windows or Linux. Finding out is like Christmas morning when you open presents... each time I hope it was branded for Windows, and also that it had been licensed for/upgraded to W10 so it has a digital license out on the Microsoft license servers for easy upgrade to W11.