I have almost all of the Find Your Fate books, just missing "Gold of Genghis Khan", but unfotunatelly I don't have a scanner, so I can't help you with the images (But yes, all the artifacts are pictured inside the book, and in most cases in the covers too.)
But I will make a list about the artifacts:
- Indiana Jones and the Curse of the Horror Island
The Artifact in this book is an "ebony idol", it's not pictured in the cover. I don't remember the plot very well... but taking a quick look at the book I can tell you that the adventure takes place in an island located at the Coral Sea and habited by the "Malekuans", who can turn out to be hostiles or not depending on your choices. The idol itself has no magical power or anything, and it also can be a priceless artifact or just one of the many identic idols made by the Malekuans, depending on your choices (quite odd, right?). But the interesting thing is: Abner Ravenwood is heavily mentioned in the book, since he also went after the idol in the past (but we learn nothing more about him).
- Indiana Jones and the Lost Treasure of Sheba
Like the title implies, there isn't an specific artifact, the treasure is pictured in the cover. In the plot we follow Indy's search for his friend: Dr. George Ballentyne, a military engineer interested in archaeology who found a map that leads to the "Treasure of Sheba". Dr. Ballentyne also created an "diamond laser capable of cutting through the hardest materials in a fraction of a second". I don't know why the hell he did that, but Ballentyne wrote a scientific article dealing with both the laser and the map (How can someone be able to work those two togheter in a single article, I don't know).
But about Sheba, a quick look at the internet told me that: "Sheba (Arabic: سبأ, Sabaʼ, South Arabian , Hebrew: שבא, Sh'va, Ge'ez, Amharic, Tigrinya: ሳባ, Saba, also referred to as the people of Tubba) was a kingdom mentioned in the Jewish scriptures (Old Testament) and the Qur'an. The actual location of the historical kingdom is disputed, with most modern evidence tending toward Yemen in southern Arabia, but a minority of other and older scholars argue for a location in either present-day Eritrea and Ethiopia. Since the two territories are separated by a narrow channel it is possible that at various times the kingdom included territory in both Yemen and later Ethiopia also, and may be equated with the Sabean kingdom." - From Wikipedia
The book places Sheba in Ethiopia, at the time part of the East Africa was under the ocuppation of Fascist forces, and they are precisely the villains here, kidnapping Dr. Ballentyne.
In most of the "happy" endings, Indy finds the treasure and decides to come back for it later, having a feeling that "they won't win this war".
We have the follow problem with the book: Indy states that he doesn't speak italian, that being the reason why he takes Dr. Ballentynes son with him: the kid does.
- Indiana Jones and the Cup of the Vampire
The artifact is the "Cup of Djemsheed, a unique medieval treasure. Legend has it that anyone who drinks from this goblet will be guaranteed eternal life". The cup is pictured in the cover. The book starts with you (a kid in a summer job at the National Museum) and Indiana Jones watching Dracula at the movie theater, when Indy's friend, Mihail Tepes (an European archaeologist), shows up asking for help. Mihail believed that his ancestor, Vlad Tepes (Second time this guy's coming back to life in an Indy story!), has found the Cup of Djemsheed and used it to stay alive. Indy tells us that the cup is made of solid gold and encrusted with jewels, that it was stolen from a mosque in Persia during the sixteenth century and lost ever since. When filled with human blood, it will give whoever drinks from it eternal life (An evil version of the Holy Graal!).
Well, I have to go now and I don't have time to finish "Cup of the Vampire" for you, but I will return for it, if that kind of information is useful for you.
Just let me know.