Owner account email is dead - cannot "Authenticate"

[GS1969a]

I lost access to my owner email address due to leaving my previous company, was a company email. I deleted the google account associated with this dead email, but this has locked me out of my tablet. I cannot "Authenticate" the owner account because the associated email account no longer exists. I tried a factory reset, but upon restart, the tablet still requests I confirm the owner.

Can I factory reset even the owner account?

[Uliwooly]

@GS1969a 

The best option is to contact the IT department of your past employer, they can probably give you access to the account, and/or contact Google directly and explain the situation.

[GS1969a]

Thank you, uliwooly, the more I look into it, the more it looks like this is the best, if not only, option..