Deprovision chromebooks from defunct enterprise

I have a batch of chromebooks that an organization donated to my robotics team. The organization is still operating, but they had an enterprise set up for these chromebooks, and they were locked to that enterprise. The enterprise no longer exists (they aren't paying for it).

I have complete permission to repurpose these chromebooks, but neither us nor the donor has any idea how to remove the lock on that organization! We can't even log in because it requires a login domain that no longer exists.

How can we deprovision these chromebooks? I've tried the "Super Powerwash", including disconnecting the battery and discharging the system. Nothing has worked, it keeps coming up with a requirement to log in with a defunct account.

Any pointers to who we might contact at google, I have full cooperation from the actual owners of these devices! Maybe there is a way to temporarily reactivate the enterprise to decommission them?