Did Joseph Smith Produce the Book of Mormon in a Matter of Months?

I've been thinking a lot lately about the production of the Book of Mormon and how it could have possibly come into existance in such a short time. Mormons claim that Smith produced it in only a matter of months, and, if that is true, is quite an amazing feat seeing as how long and detailed it is.

Could there be an alternative explanation? Hear me out.

Smith claimed that on September 21, 1823, Moroni appeared to him to tell him about the location of the buried golden plates, which contained the text of the Book of Mormon. The next morning, Smith went to the place and found the plates but was unable to take them. In fact, for the next four years, Smith met Moroni at the site and received instruction. After that time, Smith was finally granted guardianship of the plates on September 22, 1827. The Book of Mormon was published in 1830.

From 1827 to 1830... that is not a matter of months; it is three years that Smith was in possession of the gold plates. And not only that, but he was first made aware of their existance in 1823. From 1823 to 1830... that is seven (7) years.

If Joseph Smith did produce the Book of Mormon himself, there was more than enough time to write an elaborate story and do lots of research at the local library, which historians have shown that he had access to.

I have used the Joseph Smith History in the Pearl of Great Price as my source for all the dates. This means that, according to Smith himself, that he at very least, had the Book of Mormon concept for seven years before it was published. That is more than enough time to write a 531 page novel.

Smith claims, in his own words, that in order to make money, he had to travel a lot (JSH vs. 55). Who is to say that he didn't frequent all the libraries he could while away? In his head, he was formulating the story, long before he ever wrote it down.

This explains why his mother claimed that he could sit with the family and describe, in great detail, the people and customs of the Book of Mormon people. He would tell these stories BEFORE he came in possession of the plates. How could that possibly be true unless he was making up the story himself?

The evidence is right there that Smith had more than plenty of time to come up with the Book of Mormon story. He had 7 years and maybe even longer. Mormons claim, without even looking at the dates, that he only had a few number of months in which to complete the translation. But the evidence is right there, in their own scriptures, that he had at least 7 years.