Check this list an compare the CDA...
Top Sony - CDA W850

>> CDA102677/95 EUROPE_2 Generic Trade UK United Kingdom

its branded... but... i cannot say if it is locked or not...
but first at all, i think you have to upgrade your CID to 52
check this site for that.
General Information about Patch-Unlocking (start here if you want to unlock) - Top Sony Forums

first fix the screen.. and if the phone is locked.. so you can unlock it.. should not be a problem.