The lower the fill the more likely the wine is oxidized. A very high fill level in a very old vintage is indicative of excellent storage conditions. Should you be able to find a 1934 vintage, you may consider, for what it's worth, the practice I have. When I buy an old vintage, I specify the fill level at which the bottle must be and require that this be confirmed to me by the sales rep by an e-mail confirmation, based on his/her personal observation, that the wine is at the fill level that I required when the order was placed and if it is not, that there is a refund to my credit card. Your seller may not have the wine in possession at the time you place your order and, indeed, may be procuring it as a pre-arrival item that may be weeks away from delivery. So, when it is delivered to your seller, get that confirmation in writing that the fill level is as was required by your order. Should the wine be shipped and the fill level is not as required, you should easily get your money back and a reputable vendor should refund your shipping costs as well.