Flash these...

Main generic R1EA033...
Downloads - R1EA033_RED52 - W890_R1EA033_MAIN_GENERIC_AK_RED52 - Top Sony

FS WESTERN EUROPE...
Downloads - R1EA033_RED52 - W890_R1EA033_FS_WESTERN-EUROPE_RED52 - Top Sony

Custom...
Downloads - k850custpack - K850i_1201-0077_R11A_GENERIC_WESTERN-EUROPE - Top Sony
(Don't worry about this being for K850, it will work just fine)

And a tutorial...
A2-DB3150 Flashing