Multiple artifacts indicate that the Hebrews were not as monotheistic as the Old Testament claims.
Of course not, this is blatantly obvious. Just look at the wording of the Second of the Ten Commandments:
You will put no other gods before me.
This all by itself clearly shows that they believed in multiple gods, it is a far cry from what Muhammad later taught, "There is no God but God". And early on in the Hebrew theology (roughly 10th century BCE) there was a female Goddess, commonly known as Asherah. Some of that even made it into the writings of the Scriptures, such as in Jeremiah 7:16-18:
pray thou not for this people . . . The children gather wood, and the fathers kindle the fire, and the women knead [their] dough, to make cakes to the queen of heaven, and to pour out drink offerings to other gods, that they may provoke me to anger." - KJB
And later, in Jeremiah 44:15-18:
Then all the men who knew that their wives were burning incense to other gods, along with all the women who were present—a large assembly—and all the people living in Lower and Upper Egypt, said to Jeremiah, "We will not listen to the message you have spoken to us in the name of the LORD! We will certainly do everything we said we would: We will burn incense to the Queen of Heaven and will pour out drink offerings to her just as we and our fathers, our kings and our officials did in the towns of Judah and in the streets of Jerusalem. At that time we had plenty of food and were well off and suffered no harm. But ever since we stopped burning incense to the Queen of Heaven and pouring out drink offerings to her, we have had nothing and have been perishing by sword and famine. - KJB
The difference is that even in those early days, there were only 2 deities, depicted as husband and wife, King and Queen of Heaven. This is a far cry from the pantheon of deities that every other culture had at the time (as a wise man once said about the Roman Pantheon, "But we Romans are rich. We've got a lot of gods. We've got a god for everything. The only thing we don't have a god for is premature ejaculation... but I hear that's coming quickly.")
And no, anybody who has studied the Scriptures will attest that as I said they were oral history, written around the time of the Babylonian Exile. The scriptures reek of the influence of Babylon in their writings, specifically the story of Utnapishtim.
From what I gather, even though monotheism was pushed by the Priestly class, it wasn't until around the 3rd or 4th century bce that a lot of the worship of other gods was stamped out.. for example Ashereah worship. There are indications that went on to maybe as late as the 2nd century BCE.
The ancient Hebrews were never truly "Monotheistic" in the sense we know today. Rather they often believed in many gods, they simply believed
their God was the most powerful of all and they had to worship Him before any others.