I do not know for sure. But considering the facts that the translator has said that he used the original manuscript and that countess von Hartenau has donated more than 2, 000 personal belongings of Alexander to the National Museum Of Military History in Bulgaria during the 1930's, it's very likely to be in Bulgaria.
Anyway, Sandro is not Leo Tolstoy when it comes to writing, he is a soldier and he is very laconic. Most of the entries are: I got up, I was invited to luncheon with grand duke X, then we had to advance to point Y.
There are a couple of interesting moments, if you allow me to share them:
1. He has been shocked by the cruelty of the war \massacres of civilians, etc\;
2. He has been through some bad illness. His regiment has been left to starve for almost 2 days, he has written that he was so hungry that he scavenged the backpack of a dead turkish soldier and ate his stale bread. The translator applies that his death may be a postponed result from the horrible privations during this war. \He died from peritonitis. \
3. This one is very indicative of his character. During his vacations he definitely enjoyed the pleasures of life. He writes something like: “At the evening I went to the opera with X and two gorgeous ladies. After that lady Y allow me to escort her home. I returned home at the morning.” Lucky girl, lol.
4. And there was one very awkward situation, that made me laugh. It’s not a joke at all. He …. went to relieve himself in the bushes around the camp, when an angry bull came out of nowhere and started chasing him to the tents with the pants open. And he has written that, I am not making it up.