I know of one other person who has updated their 1.25" focuser to a 2" one on their Tal200K and has imaged using the Tal250K focal reducer. His name is Evgeniy and goes by the name passer_by on the Russian Tal forum
http://npzoptics.ru/forums/ (use google translator).
Have a look at one of his pictures that he took with a modified Tal200K + Tal250K focal reducer. Pretty impressive
NGC7635+M52, TAL 200K+ focus reducer, QHY8, 14 Images for 20 minutes
http://img-novosib.fotki.yandex.ru/get/5312/100245359.0/0_6b373_c6decbe_orig