although my optical bay hard drive enclosure did not use or have the bracket shown above with two Phillips #0 screws. And the hard drive had a different attachment system. The screws did not come in from the bottom. They came in from the side....no matter still a great solution.
Just added a 500 gig HD I had laying around to a 2007 Mac Mini I got on eBay.....worked like a charm. Thanks iFixit!