I have a TF-104G resin detail set. One of the panels has a corner chipped off and I cannot find that chipped off piece.

Is there a good method to repair this?

As it is a panel that covers and open compartment, I cannot use putty to cover the missing area but I have to add a tiny piece to it. There is only a very thin contact area so I don't know if super glue will be strong enough to attach a small replacement plastic,

Superglue usually is strong enough to glue small pieces of plastic to thin contact areas, especially if the part in question isn't going to be under stress. Is there any room under/behind the part? You could put in a doubler underneath to spread the gluing surface out. If there's not much room, a small piece of paper could work. Trim the broken part to a straight line to make gluing and blending in easier.

Thanks Jessica.

The part will not be under any stress.
There is not space above or underneath as this is a open panel for the fighter so it is visible from top and bottom. I think I very thin piece of paper may work if I have it cover the length of the edge of the panel.