I do something similar. I have an autoload named Globals that contains the paths and loads the assets.
const SINGLE_BULLET_TEXTURE: StreamTexture = preload("res://assets/weapons/capsule_32x16.png")
const DOUBLE_BULLET_TEXTURE: StreamTexture = preload("res://assets/weapons/double_capsule_80x16.png")
In other scripts, I can reference the items like this:
Globals.SINGLE_BULLET_TEXTURE