There are a few ways to identify Texas Specials. But to make a definite ID you will want to be able to measure the DC resistance of each pickup. Older Texas Specials will have a very overwound bridge pickup. So measuring that will be the dead giveaway. But just by looking at them you should notice that the wire used to wrap the coils is a dark purple-ish color rather than the more typical bright copper color. You would also see a vintage magnet stagger with a rather tall G-string pole and a very low B-string pole. But the old style 57/62 Reissue pickup looks like this too, so you will really want to measure the DC resistance of each pickup in the set. The old specs on Texas Specials were 7.6k for the bridge pickup, 6.5k for the middle pickup, and 6.2k for the neck pickup. The 57/62 pickup will measure at about 5.9k in all three positions.
So get yourself a multimeter and check them out. And you're right, Fender seldom puts the stickers on stock pickups. Occasionally you will see them, but usually the sticker is used just for the aftermarket pickups.
... и добавил:
Взял с форума Fеnder. Вообще-то, на японцах этих годов действительно ставили TS, так что чего уж сомневаться...