A simpler way to do it might be to combine the unique order number with an attribute value that is incremented for each ticket in an order. The customer selects ticket x with an attribute quantity 2, and the code separates those into two items with sequential attribute values at checkout. The existing code knows that if the same product is added to cart twice with different attributes, they should stay as separate items in the cart. An expert coder should be able to get something like this result without too much difficulty, and for game tickets it would probably have a quick payback.
If you have the tickets for pickup at the box office with the order confirmation number, that would work fine without any extra mods.
You would want to also check for customer name or something, so someone can't pick up another order by mistake.