Don't mod the machine. LE's are collectable. Mods are shit.
As for boxing/unboxing, it depends. For a collector, you would NEVER want to unbox the game.
For a family, who wants a working game, I'd discuss it with the buyer first. Most Stern pinballs have problems right out of the box. A certain amount of them are completely unplayable, and it's a nasty surprise if the customer is expecting a working machine to deliver a not-yet-tested machine.
For NON-LE machines, I almost insist on delivering new out-of-the-box because of the high numbers of bad software, bad flash cards, bad cpu node boards, bad node board 8's bad, bad, bad. I like to get all that fixed before the customer sees it.
But LE's are a different animal.