Heres a pic of stainless steel thumbscrews that I have been using on my headlight covers for the last year with great sucsess. They are kind of heavy and pricy($6 each) so I just use them for quick oil checking.
Macmaster Carr might list the nut serts that go in the frame.
Quick release
These might be a cheaper/lighter alternative-
http://www.mcmaster.com/param/asp/PSearch2...&McMMainWidth=0
http://www.mcmaster.com/param/asp/PSearch2...&McMMainWidth=0