Where to find the Default Email Signtature

Have you checked here:

https://support.sugarcrm.com/Documentation/Sugar_Versions/11.0/Ent/Application_Guide/Emails/#Email_Signatures

Hello Christopher Hart 


You are on the good path, this information is indeed stored in the user_preferences table. 
Try searching for the user_preferences for a given user that you know has a default signature setup and category='global':

SELECT * FROM `user_preferences`
where assigned_user_id='<yourUserID>' 
and category='global';

Let me know if this works for you. 

Cheers, 

André

Thank You so much, I found the value in the contents of global category. Really appreciate your assistance