New HD (SSD) not showing up in Finder / Question Mark Folder

I'm mystified. A few days ago my gf's 2009 MBP starting booting up showing the question mark folder. We got it to run and immediately did a complete Time Machine backup of everything on there. Two days later it stopped booting up and only went to the question mark folder.

Ordered her a 256GB SSD and pulled out her old 1TB HD. Easy day. Purchased the tools and drive from here and breezed through the HD swap.

Fired up the computer and once I get to Disk Utility it still shows the old drive. Problem being that I can "verify disk" and it still assumes that the old 1TB HD is in there...but it obviously isn't.

Time Machine backup or OSX reinstall are impossible because the Startup disk isn't showing up in Finder. I've done an SMC reset, PRAM reset, Apple Diagnostics etc...nothing is getting me closer.

Can someone advise how I can get her MBP to recognize the new SSD drive or at least remove any memory of the old 1TB HD?

Thank you for your help.