This week one of the prominent shluchim in Europe discovered one of the first copies of the Alter Rebbe's Siddur printed in Slavita in 1836. This is a very important and invaluable discovery.
The shaliach spoke with Shturem.net and related the following:
"This week I visited a very big collector of "siddurim" in Manhattan. I was surprised to discover by him the Alter Rebbe's Siddur printed in Slavita in 1836 (this is the same printing shop where the Tzemach Tzedek had written his notes on another Siddur that came out then). In addition to the Siddur I discovered that he had another 5 very old and rare siddurim that do not appear in the list of Siddurim that were ever printed.
I also noticed that he had the second edition of the Radvil Siddur. It was in excellent condition and I believe that this is the only one there is in the world.
The Alter Rebbe's Siddur that was printed in Slavita had been considered out of print and lost. It appears that this Siddur is the only one left in the world too.
This collector did me a big favor and allowed me to make a copy of the entire Siddur.
He told me that he himself davens Nusach Hoari being a descendant of Lubavitcher chssidim who immigrated to the U.S. from Russia in the beginning of the previous century.
Last year Heichal Menachem published a book called "The Siddur" authored and edited by Rabbi Gedalye Oberlander and Rabbi Nochum Greenwald. "The Siddur" came out last year to mark the 200th anniversary since the first print of the Alter Rebbe's Siddur in 1806. The book includes all the material that have been recorded throughout the years that pertain to the creation of the Alter Rebbe's Siddur and numerous articles that were written by various contemporary researchers.
One of the changes found in the Alter Rebbe's Siddur that was discovered now that there is no mention of the prayer blessing the government that is found in the other Alter Rebbe's siddurim. This Siddur also includes Selichis "B'hab" and "fast days."
The collector in Manhattan has already made contact with the editorial staff of "The Siddur" and is providing them with photo copies of the front page of every siddur he has.