How about this for proof the golden plates existed ...
From the official website of the Church of Jesus Christ of Latter Day Saints, I present to you the record of the Rajah Manchou of Vorito.
We know these plates were translated correctly because the Mormon prophet used Urim and Thummim, and an angel pronounced the completed work perfect. And we know the plates were real because we have the testimony of eleven witnesses.
Furthermore, as you can see above, the actual hole where the plates were found in a Sacred Grove on the Hill of Promise was still visible more than 60 years after an angel revealed them to the Mormon Prophet.
In case you are curious, you can see what Mormonism's god left out of the Bible and the Standard Works HERE. (Hint: It's a lot of important stuff like Baptism for the Dead, Municipal Courts, the church office of Viceroy, a city parks department, and a dress code.)
Finally, you may be interested to know almost all of Joseph Smith's remaining family, including his widow Emma, his four sons, his mother Lucy Mack Smith, his brother William, and his sisters, left the Utah Mormons and proclaimed (for a while at least) this sect the one true Mormon Church.