The mods scale with item level? do they stay at the level at which they were acquired by dismantling? Or do they scale to the item level of the weapon you craft the mod on?
Mods do not have item level of their own, they take item level from the item they are on and level up with it.
Also small clarification, not all mods scale, the damage one scale with item level. The mods like +1 charge or +20 range are constant.