If you can pin down the spot where the skip occurs, you can sometimes fix it by rubbing fairly hard in the direction of the grooves with a soft cloth wetted with isopropyl.
If you can't fix it, you can always replace it. Tonight At Noon isn't one of Mingus' more sought after releases so it can be had for not much money, unless it's the original 1965 release.
Actually, Tonight At Noon is an album drawn from two different sessions, the one that produced Oh Yeah and the one that resulted in The Clown. The tracks on Tonight are outtakes, though, so it's not a compilation in the usual sense.
Still, buying the earlier albums is a viable option because they contain much the same material as Tonight and more of it. Also, it gives you more of one of the most interesting and one of the briefest collaborations in Jazz, that of Mingus and Rahsaan Roland Kirk on Oh Yeah. As far as I know, these two unique geniuses only ever recorded here on Oh Yeah and on Mingus At Carnegie Hall. (Oh Yeah is the better showcase, IMO.)
John