Hello,
Assuming you have admin access to your installation, just head over to Menu->Administrator->RecordSets, select Premium_Projects from the dropdown and select to display only inactive records (i.e. deleted). You should see your project there and the tooltip on "i" will tell you who was the last person to update it (i.e. delete it). You can also check full edit history of the project for more details (again, including who deleted it).
In the next release (past 1.2) we're changing the behavior of RecordBrowser and Watchdog to allow users to view deleted records (without option to edit them) and receive notifications if a record you subscribe was deleted/restored.
Kind regards,
Arek