I'm continuing my way through Julius Wellhausen's Prolegomena. Today, I read (among other things) his chapter on Judges, Samuel, and Kings. Wellhausen's position seems to be that these books contain independent stories, but they are overlaid with Deuteronomistic ideology---which rebukes Israel for worshiping other gods. Although Wellhausen associates the Book of Deuteronomy with the seventh century B.C.E. reign of Josiah in Judah, he says that the Deuteronomists existed during the exile.
Here's an example, even though I'm not sure if Wellhausen is identifying the redaction as Deuteronomistic. On pages 239-240, Wellhausen discusses the story in Judges 8:22-27, in which Gideon accepts gold from Israelites and makes an ephod, after which Israel spiritually whored, and which became a snare to Gideon's house. Wellhausen states that "Studer will thus be correct in his assertion that the old tradition could not see anything in Gideon's refusing the gold for himself and dedicating it to God but a fine proof of his unselfishness and piety, and that in viii.22-27 we have a secondary product, in which the original features of the story are distorted so as to make them suit later tastes." According to Wellhausen, the original story portrayed Gideon as good for donating the gold to the worship of God, but a later hand presented Gideon's act as evil.
Wellhausen does not really document his claim, except to say that "when we consider the testimony of Hosea, Isaiah, and Micah, such images were even in the Assyrian period a regular part of the belongings of the 'houses of God' not only in Samaria but in Judah as well." Since ephods were acceptable in early layers of biblical literature, that may indicate that the original story did not deem Gideon to be wrong in donating gold to make an ephod. Wellhausen may have in mind a passage such as Hosea 3:4, which predicts that Northern Israel will be without a sacrifice, image, ephod, and teraphim. David Aaron argues that Hosea is predicting the collapse of the Israelite cult, not criticizing the contents of that cult, which was like that of most cults---it has an ephod, teraphim, etc. Even righteous Judah had graven images---the cherubim of the Ark of the Covenant---and God not only approved of this, but commanded it. Moreover, there are passages in which David consults or wears an ephod (I Samuel 23:6-9; 30:7; II Samuel 6:14). Apparently, ephods were not considered to be wrong at a certain layer of ancient Israelite religion!