Russia bought 122mm howitzers from Krupp and Schneider, using them as m09 resp. m10. These were discussed here: http://www.activeboard.com/forum.spark?aBID=63528&p=3&topicID=14298054
After reading that informative, if somewhat confusing thread, and Wikipedia, Landships and jaegerplatoon, I have a couple of questions about those guns and hope you could help finding the answers:
Am I correct to assume that the m10 was the more common one, and the only one upgraded for WW2 use? http://en.wikipedia.org/wiki/122_mm_howitzer_M1910/30
Did the m10 always have the double shield (one flat plate, with another curved one in front of the lower part of it)? Or could they be left off as in Brennan's most inspiring conversion http://www.hat.com/Othr8/Brennan01P.html ?
Were there any other regular users apart from the Russians? Not talking of occasional booty pieces here as used by German and Finnish troops. It seems odd to me that neither were the Germans using the Krupp gun, nor the French the Schneider gun.
I found an extensive answer to my own question about the French-made howitzer in an article in GBM No. 76, which is based on the book "Les Canons de la Victoire 1914-1918". This might be of interest for others, too, so here is a summary.
France sold these howitzers to Bulgaria. By the time the Creusot factory had them ready, Bulgaria had joined the Central Powers, so France confiscated the eleven batteries of these guns. It did not receive a standard appellation but the name obusier de 120 Schneider, or canon de 120 CTR.
These howitzers, according to GBM the only ones of this type used by the French, were the allocated to the artillerie lourde hippomobile (ALH) and used by the 103e RALH. Beginning with November 1915, The 1st, 2nd and 3rd batteries served at the Somme until February 1916, then at Verdun, and 1917 at Chemin-des-Dames. The 4th and 5th battery were created in January 1916 and fought at the Aisne until August 1916.
The howitzers then were sent to the Armée d'Orient in the Balkans, were they ironically fired onto the troops for whom they had originally been ordered: the Bulgarians. The howitzers were later passed on to Serbia. Regards, Pat