Vauxhall Corsa C 1.2 Z12XE Easytronic Fault Code P1728?

Hello Everyone, Merry Christmas to you All.
I know there is lots of answers to this question.
But not seen any proper answer to actual Fault / Problem.
Mine is 2001 Corsa C as above, F - Fleshing, Car stuck in 4th gear, not coming out of gear despite turning screw on clutch actuator. as soon as you turn ignition key on it goes back in 4th gear, I have replaced with second hand Bosch Pair of gear seclector motors.
in mine, there is a oil leak in bosch motor and carbon brushes worn out, ARE this Repairable? where can I find oil seal and carbon bruses?
can we swap with second hand clutch actuator ECU? can we reprogram DIY? with TEC2. if I want to buy an OPCOM, Any suggestion pls.
Thanks
pjnumnerone