I used to have a tape by Brother Larry T Smith which was a study he did years ago on the Urim and Thummin.
It has been a long time since I heard it (10-12 years... maybe 15) and I can no longer remember the points that he made but I do remember it being a very enjoyable and enlightening study.
His various forms of contact are located on this page.
Even though it has been that long ago I feel sure he would still have it available. It was one of his mainstay studies for quite a while.
http://www.rightlydividingtheword.com/contact.htm