Webster at State.
I don't actually think Cass would be there - he's a Democrat.
Crittenden would definitely be retained and promoted, perhaps to Treasury since he has no real military qualifications. Alas, I don't think he has any particular qualifications for Treasury either. John Bell may be brought back for War.
Joseph Vance of Ohio is a good choice for Cabinet. His electoral career has run its course, but he's done a lot for the Whigs and can be allowed to go out on a high note. What position remains to be seen.
Clay will need a New Yorker; let's see who Governor Seward thinks he can part with...hmm...sitting Congresscritter Charles H. Carroll looks like a good choice, and Seward can stick the up-and-comer Hamilton Fish in his place. Clay is likely to create the post of Secretary of the Interior, and Hugh White of New York (1798-1870) would be a good first SecInt.
Need to fill Navy and Postmaster, and Clay needs a deep south man. Hmm. Vance can be Postmaster (or War if Bell wasn't retained...yeah, I like that better. Vance at War, a Kentucky crony as PMG.), but a southern navy man...who's Port Authority in Charleston? Or a Virginian?