You would have minors listed as beneficiaries, not as trustees. And as far as I know, there is no stipulating which items "belong" to whom. Think of it as the trust being a legal entity that owns the NFA items, not the individuals named in the trust (whether that's technically right or wrong, it may help you get the picture).
Here are some related products that TexasGunTalk members are talking about.
Clicking on a product will take you to TexasGunTalk’s partner,
where you can find links to TexasGunTalk discussions about these products.