I've been using "Cobra" covers for years, so if it's the same dimensions, it'll fit.
So a Cobra differential cover is a direct bolt on for a Thunderbird cover? If so, yes, this Fore cover would be a bolt on affair.
Yes, Cobra covers bolt right on.
I can't comment on this particular piece but I know that the Control Freak cover I have WILL NOT fit a Cobra, nor will the stock T-bird piece. You'll be able to bolt a Cobra cover to the diff housing, but bolting the Cobra cover to the T-bird rear mount shouldn't work.