Alex, yes I did see the exhibition and have a copy of the catalog with the badge illustrated. The illustration is just of the front half. I cannot scan it for you but will give you a copy of the description:
"753 ENAMELED SILVER COMMEMORATIVE BADGE shaped as a Maltese cross with central cipher of Tsar Nicholas II on green guilloche enamel ground, inscribed and dated "Commemorating the 50th Avviversary of the Land Reform 19 February 1861-29,March 1911, 1906 - signed Faberge, initials of workmaster Alfred Thielmann, 1908-1917, height 2 1/8 inches (5.4cm)
Bibliography: S.B. Patrikyeev & A.D. Boynovich, "Badges of Russia". Farn Moscow/St. Petersburg 1995 p. 332, no.12.6 (another example). Private Collection"
As I said Thielmann specialized in small pieces of jewelry (tie pins, miniature eggs, small brooches, etc.) and badges. Perhaps the making of these specific badges was an Imperial commission? The Faberge firm could have been contracted to make all of the badges. Or, the situation could have been that an individual who was awarded the badge wanted a little finer one and commissioned the Faberge shop to make one? If you say that this badge is rare, do you know about how many were awarded? If it were a small number then the Faberge firm could have been awarded the commission to make these. If there were 500 or 1,000 produced I doubt if the Faberge firm would have been awarded the commission as the cost would have been prohibitive to the Imperial Court and the Court would have awarded the commission to a silver workshop that did this type of work more frequently and on a larger scale. Faberge produced this kind of thing in smaller numbers with high quality materials and hence the price would be higher.
It is quite a treasure.