There are plenty of threads on the matter so I will just add that a branded Lucas insert did the job nicely for about £35, no clue as to country of origin but still sealed from date 2016. The original Bosch seemed to have lost it's thermistor. Removing the 5-point torque screws was a pig (without the bits) but I just cut a slot with a Dremel-type carborundum disc and replaced the originals with S-S posidrive.