Here is the place you can pick-up a metal T-38 cardback to hang your AT-38B tag from! These cards are offered in 2 variants: hinged and un-hinged. These cards were cut from belly access panels that were hinged to allow for easy access/maintenance to the engine. The hinged cards feature part of the hinge mechanism. Tag not included. 

T-38 Talon Metal Cardback for AT-38B Aircraft tags