This is my first go-around with an HP hardware issue of this nature, but I am a systems engineer by trade, so I'm not afraid of poking around. Going through the BIOS, I can see the SKU and Serial Number are still intact and I have the CT number recorded on a sticker inside the OEM case.
I own an HP ENVY 750 that randomly lost its System Board CT Number.
If I need to create a separate post, or post in another thread/area, please just let me know. I am struggling, but I feel this thread has information I need to put me on the right track.