I am wondering how the temple property and artifacts were handled and disposed of when the Church left Nauvoo?
I believe that the Mormon Church made no formal disposition of the materials and artifacts that were in the Nauvoo Temple. You will remember that they were forced by armed mobs to flee from their homes while the temple was being cannonaded. James E. Talmage, in his Articles of Faith, Ch.7, p.155, stated that “The Temple at Nauvoo was destroyed through malicious incendiarism.” So I imagine that it was probably looted by the mob and then burned.
President Joseph F. Smith was a boy of about six years old when the exodus came. Here is an excerpt from his account of the event–
I can remember the time when I was quite a little boy, when we were hurried very unceremoniously across the river Mississippi from the city of Nauvoo just previous to the bombardment of the town by the mob. I had a great anxiety then–that is for a child–to know where on earth we were going to. I knew we had left home. We had left it willingly–because we were obliged to–we left it in a hurry, and we were not far away when we heard the cannonade on the other side of the river (Journal of Discourses, Vol.24, p.150 – p.154, Joseph F. Smith, December 3, 1882).