The .ja files need to be renamed then moved into the TSR12 "Built in" folder.
This is correct, except that you don't need to rename anything.
My moved files are now called 1.ja to 8.ja, BaseTs10.ja & DataTs10.ja
The TS2010 "Base" and "Data" JA files should not be copied across. They'll do nothing beneficial.
kind regards,
chris