From various sources, mainly two books by Vitalii Ivanovich Fes'kov:
1) Krasnaia Armiia v pobedakh i porazheniiakh, 1941-1945 gg.
2) Sovetskaia Armiia v gody "kholodnoi voiny" (1945-1991)
as well as the "Boevoi sostav Sovetskoi Armii" which is a monthly order of battle for the Soviet Armed forces 1941 to 1945.
Extracts from this (every 3 months) has been published here: http://victory.mil.ru/war/oob/index.html
The 207th Tank Regiment was part of the 32nd Smolenskaya, Red Banner and order of Suvorov II st. Cavalry Division. This division served together with the 5th Guards Cavalry Division under the 3rd Guards Cavalry Corps.