I fall in to the category of saying DO NOT OPEN.
The question is whether someone is willing to pay more for unopened vs opened. I say YES mainly because once it is opened it risks damage and marring to the finish. Since you are asking value I'm assuming you plan to sell this. I would believe that at a serious auction a Texaco aficionado would pay more for yours than one which has been displayed.
Remember, it's only original packaged once and unless no one wants to pay for that packaging it's better to leave as is and sell as is.
BTW, for anyone who think packaging in signs doesn't matter I point them to the highest price ever paid for a Coca Cola Policeman... sealed in box.
