If it were the true doubled die obverse you would really be able to tell: There is also the poor mans doubled die for this date that is worth significantly less (not much of a premium) than the true doubled die:
Actually there is one other 1955 DDO-002 that is really quite impressive itself. And there are quite a few 1955 Proofs that are DD. So keep on looking at that year even if it isn't #1.