Suggestion: pry open the gap between this bar and the hood sheet metal, squirt in some PL-series urethane construction adhesive (the nastier, the better) in the gap, and then close the hood half-way onto a 2x4 (end-wise) atop the engine. The weight of the hood resting on the 2x4 (which is sitting on this loose support) will help squeeze the support bar tightly against the hood sheet metal. If you own an FJ55 or 60, you'll see the same delamination problem.
However you do it, get gentle weight on the hood against the support bar to squeeze out the excess bonding agent.