first off, what system are you looking for said truck in? If it isnt the dealer daily system at a dealership, then it doesnt mean much
also, if a dealer has been allocated that truck and put it in reserve status then you are right, it would not show up on anyones report except the dealer that has it on reserve. But they would sure be able to tell you that.
as far as your trade in money is concerned, two things , one is that I cant really speak for how that region does something so I wont even guess. Two is it isnt what incentives are available when you order the truck, it is what incentives are current when the truck gets here. They could go up or down by then.
who at the dealership did you order the truck from? No one with any brains at all would have told you that a order truck would take 2 weeks. I would have told you 2 months if we are lucky and 4-5 if it is a really different configuration.
if you say that there are not any trucks in your entire region, it wont matter what volume dealer you are at if you are trying to get one quickly. But a high volume dealer can try to change one inbound to come in like yours and has a good shot of getting it unless you have a weird combo for that region.
This may be the time to give up on the jbl system and get a truck sooner and add your own suped up system later.