Where can I purchase a paired logic board & home button combo?

My iPhone 6 got minor water intrusion, and it went dead. I immediately turned it off and dried it our with a blower. The next day I powered up and after a few minutes it turned itself off and never powered up again.

I purchased a new phone as I was traveling. The phone sat off for a couple of months and finally I got around to work on it. I replaced the L/C module, and cleaned the connector to the home button. As it can be seen in the pictures below. There is no major water damage.

The phone powered up and works fine, however the Touch ID setup fails, and the iOS fails to update. I never replaced the touch ID/home button.

My next step is to replace the touch ID/Home Button cable flex that is behind the screen shield.

Other than that, my only option is to purchase a paired logic board / Touch ID-Home button. Any idea where I can get an AT&T paired logic board with Touch ID-home button assy.?

Has anyone resurrected the touch id button by dunking in alcohol to clean it up?