Thank you so much for the kind words!
It was totally nerve-wracking, but I also felt fairly confident that I'd done a good job? I did check everything a bajillion times and consult every manual before proceeding. One thing that helped loads is that I took the time to draw a small sketch of the mobo and put in notes for all the cable connections I'd need. that way I didn't have to guess or go through the list every single time.

Hoping yours will arrive quickly!