The hood is in good shape and the rear one piece brace looks fine. It's just that when the front is latched the back part of the hood still has a pretty good gap to the fender. I'll work on it...now that i know the latches are owner-added...
I would throw out a caution flag at this point. I just need some clarification. You say that when the front is latched, there is a pretty good gap at the back. I'm not sure that putting more latches on will solve that. The gap between the hood and fender should be a constant 3/8 - 1/2 inch all along the fender, if it varies front to back its most likely that your fenders are not on straight, I would start there and make sure that they are straight.
Next question is what problem are we solving for now? Is the hood flapping, rubbing, or is there a deep vibration sound at a specific idle. I thought I needed a second set of latches, after I fixed the fenders I found that the hood didn't make noise anymore and the rubbing went away. I did have a deep vibration sound that turned out to be the baffle in the fuel tank, vibrations at a harmonic, I added some isolators to move the tank off of the floor and that went away as we'll.
If you need a nice set of stainless steel polished hood latches let me know, I have a set to sell.
Todd